# Nepal Investment Mega Bank (NIMB) Cybersource Payment Gateway Integration – WebApp Nepal > WebApp Nepal integrates Nepal Investment Mega Bank's Cybersource gateway to accept international Visa and Mastercard payments, including 3D Secure and refunds, settled in NPR. Source: https://webappnepal.com/service/nimb Provider: WebApp Nepal, Kathmandu, Nepal Updated: 2026-08-07T21:07:55.000000Z A Kathmandu-based online retail business spent two years turning away international Visa and Mastercard payments because their payment infrastructure only supported eSewa and Khalti. Nepali digital wallets served the domestic market well - but international buyers, returning tourists, and diaspora customers wanted to pay with a card. The owner had heard that accepting cards required a foreign bank account, a complicated licensing process, or a large upfront merchant service fee that only enterprise businesses could justify. Then she was introduced to Nepal Investment Mega Bank's payment gateway - a bank-issued merchant payment solution powered by Visa's Cybersource platform that allows Nepal-registered businesses to accept Visa and Mastercard cards directly, with funds settling into a Nepal rupee account at NIMB. The licensing complexity she had feared turned out to be a standard business bank account opening process. The card-paying international market she had been leaving untouched opened within weeks of the integration going live. Nepal Investment Mega Bank's payment gateway, built on Visa's Cybersource payment management infrastructure, represents one of the most credible paths for Nepal businesses to accept international card payments while maintaining a fully Nepal-based banking relationship and NPR settlement. Unlike setting up a foreign Stripe or PayPal account - which requires navigating foreign tax residency questions and international bank accounts - the NIMB payment gateway is issued by a Nepal-licensed commercial bank, regulated under Nepal Rastra Bank's framework, and settles transactions in Nepali rupees to a NIMB merchant current account. For Nepal businesses that need to accept Visa and Mastercard from international customers but want to operate entirely within Nepal's banking and regulatory environment, NIMB's Cybersource-powered gateway is the correct infrastructure choice. #### What Is the NIMB Cybersource Payment Gateway? Nepal Investment Mega Bank (NIMB) is one of Nepal's established commercial banks operating under Nepal Rastra Bank (NRB) licence. NIMB issues payment gateway services to Nepal-registered merchant businesses, allowing those merchants to accept card payments - Visa, Mastercard, and in some configurations American Express - on their websites and applications. The underlying technology infrastructure is Cybersource, a Visa company that provides payment management, fraud detection, and tokenisation services to banks and merchants globally. When a customer pays on a NIMB gateway-integrated Nepal website, the card transaction is processed through Cybersource's global payment network, authorised by the card-issuing bank, and settled to the Nepal merchant's NIMB account in NPR at the prevailing exchange rate. This architecture gives Nepal merchants access to world-class payment processing infrastructure - Cybersource processes billions of transactions annually for global banks - while keeping the merchant relationship, compliance obligations, and fund settlement within Nepal's banking system. The merchant does not need a foreign bank account, does not need to register a business entity overseas, and does not need to navigate foreign payment processing regulations. The NIMB relationship is a Nepal bank relationship governed by Nepal law, with the Cybersource infrastructure operating transparently underneath. #### How NIMB Cybersource Gateway Differs from eSewa and Khalti ##### Card Acceptance vs Wallet Acceptance eSewa and Khalti are Nepal digital wallet platforms - customers must have an eSewa or Khalti account loaded with NPR balance to pay. International buyers, tourists, and diaspora customers who do not have a Nepal digital wallet account cannot use these payment methods. NIMB's Cybersource gateway accepts Visa and Mastercard cards from any issuing bank in any country - a UK-issued Barclays Visa, an Australian Commonwealth Bank Mastercard, a US-issued Chase Visa - without requiring the cardholder to have any Nepal banking relationship. For Nepal businesses targeting international buyers, this is the critical difference: NIMB gateway opens the international card-paying market that eSewa and Khalti structurally cannot reach. ##### NPR Settlement in a Nepal Bank Account International card payments processed through NIMB's gateway settle in Nepali rupees to the merchant's NIMB current account after the applicable merchant discount rate (MDR) deduction. This NPR settlement to a Nepal bank account distinguishes NIMB gateway from Stripe or PayPal, which typically require settlement to a foreign bank account in a foreign currency. For Nepal businesses that need to repatriate foreign earnings - which requires NRB-compliant foreign currency documentation under Nepal's foreign exchange regulations - the NIMB gateway simplifies the process because the settlement is already in NPR within the Nepal banking system, eliminating the foreign exchange conversion and repatriation paperwork that comes with foreign gateway settlements. ##### NRB Regulatory Compliance Nepal's foreign exchange regulations require that businesses earning foreign currency from international trade follow NRB's repatriation and reporting guidelines. A Nepal business accepting USD payments through a foreign Stripe account into a foreign bank account is operating in a regulatory grey area under NRB's foreign exchange management rules. NIMB's gateway processes the currency conversion at the bank level and settles NPR to the merchant - keeping the transaction within the NRB-regulated banking framework from the outset. For Nepal businesses that want certainty about their regulatory compliance when accepting international card payments, the NIMB gateway's Nepal-bank-issued structure provides that certainty in a way that foreign gateway accounts do not. #### Cybersource Integration Methods ##### Secure Acceptance Hosted Checkout Cybersource's Secure Acceptance Hosted Checkout is the integration method most appropriate for Nepal businesses without dedicated payment engineering teams. In this integration, the merchant website collects order details and redirects the customer to a Cybersource-hosted payment page - where the customer enters their card details directly on Cybersource's PCI DSS Level 1 certified environment. The card data never passes through or touches the merchant's server, which eliminates the merchant's PCI DSS card data handling obligations and reduces compliance scope to the simplest SAQ A self-assessment. After the transaction is processed, Cybersource redirects the customer back to the merchant's website with a signed transaction result. The merchant backend validates the signature of the returned result before updating order status - preventing result parameter manipulation. WebApp Nepal implements Secure Acceptance Hosted Checkout with correct result signature validation, order status management, and confirmation email triggering on the post-redirect callback. ##### Secure Acceptance Web/Mobile SDK For merchants who need card data collection embedded directly within their website rather than via a redirect to a Cybersource-hosted page, Cybersource's Secure Acceptance Web SDK provides a tokenisation approach: card data is entered in a gateway-hosted iframe embedded within the merchant's page, tokenised by Cybersource's servers, and a non-sensitive token is returned to the merchant's JavaScript for inclusion in the payment request. The actual card number and CVV are captured by Cybersource's PCI-certified infrastructure, not the merchant page. WebApp Nepal implements the Web SDK integration for merchants where the user experience continuity of staying on the merchant's site throughout checkout is a priority - typically hotel and trekking booking platforms where the checkout flow is part of a carefully designed inquiry-to-booking conversion funnel. ##### REST API Integration Cybersource's REST API provides the most flexible integration path for complex Nepal web applications - subscription billing platforms, multi-step booking systems with pre-authorisation and capture, marketplace platforms managing payments across multiple sellers, and systems requiring programmatic refund management and transaction reporting. REST API integration uses HTTP Signature authentication with the merchant's key ID and shared secret, and supports the full range of Cybersource transaction types: authorisation, capture, authorisation reversal, refund, and void. WebApp Nepal builds Cybersource REST API integrations for Nepal web application projects where the transaction lifecycle management requirements go beyond what hosted checkout can handle - for example, hotel booking systems that pre-authorise the card at booking and capture the full charge at check-in, or subscription platforms that tokenise cards at signup for recurring monthly billing. #### Key Technical Implementation Details ##### Transaction Result Signature Validation After a Cybersource Secure Acceptance transaction, the customer is redirected back to the merchant's result URL with a set of signed parameters including transaction status, reference number, and authorisation code. These parameters include a signature field - an HMAC-SHA256 hash of the returned parameters computed using the merchant's secret key. Validating this signature before trusting the transaction result is the critical security step that prevents result URL manipulation: without signature validation, a technically-minded customer could modify the URL parameters to make a failed or cancelled transaction appear successful. WebApp Nepal's Cybersource integrations validate the return signature on the server side, not in client-side JavaScript, before any order is marked as paid. ##### 3D Secure Authentication 3D Secure (3DS) is the card network authentication protocol - Verified by Visa, Mastercard SecureCode, American Express SafeKey - that adds an additional authentication step for online card transactions where the card-issuing bank requires it. For international cards paying Nepal merchants, 3DS challenges are common because cross-border transactions carry elevated fraud risk scores at the issuing bank. Cybersource supports both 3DS 1.0 and the current 3DS 2.x standard, which enables frictionless authentication (no customer action required) for low-risk transactions and step-up authentication (OTP or biometric) for high-risk ones. WebApp Nepal configures 3DS correctly in NIMB gateway integrations so that authentication challenges appear within the payment flow rather than as unexplained transaction failures - the difference between a customer completing a slightly inconvenient authentication step and abandoning the checkout entirely. ##### Currency Configuration and DCC NIMB gateway processes transactions and settles in NPR to the merchant's NIMB account. For international customers, the transaction may be presented in their card's billing currency through Dynamic Currency Conversion (DCC) if the bank has enabled it - or in NPR, with the currency conversion handled at the card-issuing bank side. WebApp Nepal advises merchant clients on currency display configuration for their checkout: displaying prices in USD (or the target customer's currency) while the gateway processes in NPR creates a better international buyer experience than displaying NPR prices to buyers whose mental model is in USD or EUR. The correct currency display strategy depends on the merchant's primary international market. ##### Transaction Reference and Reconciliation NIMB gateway transactions generate a Cybersource transaction reference number for every processed payment - successful, declined, or reversed. Building this reference number into the merchant's order record at the time of transaction is essential for financial reconciliation: matching the merchant's order management records to the NIMB bank statement and Cybersource merchant portal transaction logs. WebApp Nepal stores the full Cybersource transaction payload - reference number, authorisation code, card type, last four digits, response code, and timestamp - against every order record, enabling reconciliation without relying on memory or manual cross-referencing between systems. ##### Refund Processing via Cybersource Card refunds through NIMB gateway are processed as Cybersource credit or void transactions. A void cancels an authorisation that has not yet been captured - appropriate within the settlement window, typically 24 to 48 hours. A credit (refund) is processed against a captured transaction and routes the refund back to the original card. The timeline for the refund to appear on the cardholder's statement depends on the card-issuing bank - typically three to seven business days for international cards. WebApp Nepal builds admin-facing refund initiation into merchant platforms integrated with NIMB gateway, so that processing a refund is an action in the merchant's own admin panel rather than a manual operation in the Cybersource merchant portal. #### NIMB Merchant Account Requirements To use NIMB's payment gateway, a business must hold a NIMB merchant current account. The account opening process requires the standard Nepal commercial bank documentation: company registration certificate (for private or public limited companies), PAN certificate, memorandum and articles of association, board resolution authorising the designated signatories, citizenship documents of directors or authorised signatories, and a completed NIMB merchant application form. For sole proprietorship or individual businesses, the documentation set is lighter. NIMB's merchant banking team reviews the application and conducts the standard KYC process before issuing the merchant credentials - the merchant ID, key ID, and shared secret - that are required for the Cybersource API integration. The timeframe from application to credential issuance varies but typically ranges from one to three weeks. WebApp Nepal advises clients on the documentation preparation and can guide the merchant account application process, though the account must be held by the client business. #### Merchant Discount Rate (MDR) and Settlement NIMB charges a merchant discount rate on card transactions processed through the gateway - a percentage of the transaction amount that covers the bank's payment processing costs, the card network's interchange fee, and the Cybersource processing fee. The MDR varies by card type (Visa domestic, Visa international, Mastercard international) and by merchant category. International card transactions typically carry a higher MDR than domestic card transactions due to higher interchange fees. Settlement of processed transactions - net of MDR - happens to the merchant's NIMB current account on a schedule agreed at merchant account opening, typically one to two business days after the transaction date. WebApp Nepal helps clients understand the MDR structure and factor it into pricing and margin calculations before launching the gateway integration, rather than discovering it as a surprise deduction after go-live. #### Industries Using NIMB Cybersource Gateway in Nepal ##### Tourism and Trekking Nepal's trekking agencies, hotels, resorts, and adventure operators are the most frequent users of NIMB gateway integration. International trekkers and tourists are accustomed to paying travel deposits and bookings with Visa or Mastercard and are uncomfortable with alternatives that require creating a Nepal digital wallet account. NIMB gateway allows Thamel-based trekking agencies to take USD trek deposits directly from a European or North American customer's card, with NPR settlement into the agency's Nepal bank account. Hotel direct booking systems accepting room pre-payment from international guests without OTA commission use NIMB gateway for the same reason: the international guest pays with the card already in their wallet. ##### Export E-Commerce and Handicrafts Nepal's export-oriented e-commerce sector - Dhaka textile sellers, Thangka and Paubha painting galleries, Pashmina retailers, handmade jewellery and craft stores - needs international card acceptance to reach buyers who discovered Nepali products as tourists and want to purchase again from abroad. NIMB gateway enables this card-paying international buyer segment without requiring the merchant to hold a foreign bank account. Craft and artisan businesses operating from Patan, Bhaktapur, and Thamel with significant international buyer interest use NIMB gateway as the foundation of their international e-commerce payment infrastructure. ##### Educational Institutions with International Students Nepal's private schools, boarding schools, and colleges with international student enrolment - students from neighbouring countries, Tibetan students, and international students on cultural or language programmes - need fee collection mechanisms that work for non-Nepali payers. NIMB gateway allows these institutions to accept tuition and application fee payments from international Visa and Mastercard holders, settling the payment in NPR to the institution's NIMB account. ##### NGOs and INGOs Receiving International Donations Nepal-registered NGOs receiving international donations from individual supporters (as opposed to institutional grants) benefit from card payment capability because individual international donors are accustomed to one-click card donation flows. NIMB gateway provides Nepal NGOs with card donation acceptance that settles in NPR within Nepal's banking system - simpler from an NRB foreign exchange compliance perspective than managing foreign currency in a foreign bank account. #### NIMB Gateway Integration Pricing at WebApp Nepal NIMB Cybersource gateway integration pricing depends on the integration method and the complexity of the surrounding checkout flow. A Secure Acceptance Hosted Checkout integration - redirect-to-NIMB-page, signature validation, order status update - added to an existing website typically costs NPR 35,000 to NPR 55,000. A Web SDK integration with embedded card collection, full order lifecycle management, admin refund panel, and Cybersource transaction logging costs NPR 55,000 to NPR 90,000. A REST API integration for complex transaction flows - pre-authorisation and capture, subscription tokenisation, marketplace multi-party settlement - is scoped individually based on the transaction flow requirements but typically ranges from NPR 80,000 to NPR 1,60,000. Integration as part of a new trekking, hotel, or e-commerce website project is included within the overall project scope. All NIMB gateway integrations include 3DS configuration, transaction reference logging, sandbox testing, and security review before production launch. Nepal businesses that have been accepting eSewa and Khalti successfully but losing international card-paying customers to competitors or OTAs now have a clear infrastructure path: NIMB's Cybersource-powered gateway, issued by a Nepal-licensed bank, settling in NPR, and fully integrated into a Nepal business banking relationship. WebApp Nepal has implemented this integration for tourism businesses, export retailers, and institutional clients who needed exactly this combination of international card acceptance and domestic banking compliance. The technical implementation is one project. The international card-paying market it opens is an ongoing commercial asset. Reach out to discuss your NIMB gateway integration requirements and we will scope it correctly before development begins. ## Frequently asked questions ### What is the NIMB Cybersource payment gateway? Nepal Investment Mega Bank (NIMB) issues a payment gateway service to Nepal-registered merchant businesses, built on Visa's Cybersource payment management platform. It allows Nepal merchants to accept Visa and Mastercard card payments from any international cardholder on their websites and applications, with transaction settlement in Nepali rupees (NPR) to the merchant's NIMB current account. It is one of the most compliant paths for Nepal businesses to accept international card payments within Nepal's NRB-regulated banking framework. ### How is the NIMB gateway different from eSewa and Khalti? eSewa and Khalti are Nepal digital wallet platforms - customers must have a Nepal wallet account with NPR balance to pay. International buyers without a Nepal wallet cannot use them. NIMB's Cybersource gateway accepts Visa and Mastercard from any issuing bank in any country - a UK Barclays Visa, an Australian Mastercard, a US Chase Visa - without requiring any Nepal banking relationship from the buyer. For Nepal businesses targeting international customers (tourists, diaspora buyers, foreign donors), NIMB gateway opens the card-paying international market that eSewa and Khalti structurally cannot reach. ### Why should a Nepal business use NIMB gateway instead of Stripe or PayPal? Stripe and PayPal typically require settlement to a foreign bank account in a foreign currency, raising NRB foreign exchange repatriation compliance questions for Nepal businesses. NIMB gateway settles in NPR directly to the merchant's Nepal bank account at NIMB, keeping the entire transaction within Nepal's NRB-regulated banking framework. This eliminates foreign currency repatriation paperwork, foreign tax residency questions, and the regulatory uncertainty of operating a foreign payment account for a Nepal-based business. For Nepal businesses that want international card acceptance with full Nepal banking compliance, NIMB gateway is the structurally correct choice. ### What is Cybersource and why does NIMB use it? Cybersource is a Visa company providing payment management infrastructure - transaction processing, fraud detection, tokenisation, and 3D Secure authentication - to banks and enterprises globally. NIMB uses Cybersource as the underlying technology for its merchant payment gateway because Cybersource is a PCI DSS Level 1 certified payment processor with global card network connectivity. Nepal merchants using NIMB gateway benefit from Cybersource's processing infrastructure without needing a direct relationship with Visa's technology platforms. ### What integration methods does Cybersource offer for Nepal merchants? Cybersource (via NIMB) offers three main integration methods: (1) Secure Acceptance Hosted Checkout - the customer is redirected to a Cybersource-hosted payment page, card data never touches the merchant's server, lowest PCI compliance burden. (2) Secure Acceptance Web/Mobile SDK - card data is collected in a Cybersource-hosted iframe embedded within the merchant's own page, providing better UX continuity. (3) REST API - full programmatic control for complex transaction flows including pre-authorisation, capture, subscription tokenisation, and refund management. WebApp Nepal implements all three methods depending on the merchant's requirements. ### Does NIMB gateway require a separate bank account? Yes. To use NIMB's payment gateway, a business must hold a NIMB merchant current account. Account opening requires standard Nepal commercial bank documentation: company registration certificate, PAN certificate, memorandum and articles of association, board resolution, and director citizenship documents. For sole proprietors, the documentation is simpler. NIMB's merchant banking team conducts the standard KYC process and then issues the merchant credentials (merchant ID, key ID, shared secret) required for Cybersource API integration. The account opening process typically takes one to three weeks. ### Can WebApp Nepal integrate the NIMB Cybersource gateway into an existing website? Yes. NIMB Cybersource gateway integration can be added to an existing website without rebuilding it, provided the site has appropriate backend architecture for payment initiation and result handling. WebApp Nepal assesses the existing site's technical stack before scoping the integration. WordPress sites receive integration via custom plugin or API extension. Custom-coded sites receive direct backend integration. A Secure Acceptance Hosted Checkout integration added to an existing site typically costs NPR 35,000 to NPR 55,000 and takes two to three weeks including sandbox testing. ### What is 3D Secure and how does it work with NIMB gateway? 3D Secure (3DS) is the card authentication protocol - Verified by Visa, Mastercard SecureCode - that adds an identity verification step for online card transactions where the card-issuing bank requires it. For international cards paying Nepal merchants, 3DS challenges are common because cross-border transactions carry elevated fraud scores. Cybersource supports both 3DS 1.0 and 3DS 2.x (which enables frictionless authentication for low-risk transactions). WebApp Nepal configures 3DS correctly so challenges appear within the payment flow as a natural authentication step rather than as unexplained failures that cause customers to abandon checkout. ### How does transaction settlement work with NIMB Cybersource gateway? Transactions processed through NIMB's Cybersource gateway settle in Nepali rupees (NPR) to the merchant's NIMB current account, net of the merchant discount rate (MDR). The currency conversion from the cardholder's billing currency (USD, GBP, EUR, etc.) happens at the bank level. Settlement typically occurs one to two business days after the transaction date, on a schedule agreed at merchant account opening. The NPR settlement to a Nepal bank account eliminates the foreign exchange repatriation process that would be required if the merchant were settling into a foreign currency account. ### What is the merchant discount rate (MDR) for NIMB gateway? The merchant discount rate (MDR) is a percentage of each transaction that NIMB deducts before settling to the merchant account, covering the bank's processing costs, card network interchange fees, and Cybersource processing fees. The exact MDR varies by card type (domestic Visa, international Visa, Mastercard international) and merchant category. International card transactions typically carry a higher MDR than domestic transactions due to higher interchange fees. NIMB's merchant team provides the specific MDR schedule at merchant account opening. WebApp Nepal helps clients understand the MDR before go-live so pricing and margin calculations account for it. ### How does WebApp Nepal validate NIMB gateway transaction results? After a Cybersource Secure Acceptance transaction, the customer is redirected back to the merchant's site with signed result parameters including an HMAC-SHA256 signature computed from the returned fields using the merchant's secret key. WebApp Nepal validates this signature on the server side before trusting the transaction result - unsigned or invalid-signature results are rejected. This prevents result URL manipulation where a malicious user could modify redirect parameters to make a failed transaction appear successful. Server-side signature validation is a mandatory security step that WebApp Nepal treats as non-negotiable in every NIMB gateway integration. ### Does the NIMB Cybersource gateway support refunds? Yes. Card refunds through NIMB gateway are processed as Cybersource void or credit transactions. A void cancels an uncaptured authorisation within the settlement window (typically 24–48 hours). A credit (refund) is processed against a captured transaction and routes the refund to the original card - typically appearing on the cardholder's statement within three to seven business days. WebApp Nepal builds admin-facing refund initiation into merchant platforms, so refunds are processed from the merchant's own admin panel rather than requiring manual operation in the Cybersource merchant portal. ### Is the NIMB Cybersource gateway PCI DSS compliant? Cybersource is a PCI DSS Level 1 certified payment processor - the highest certification level in the card industry. For Nepal merchants using Secure Acceptance Hosted Checkout or the Web SDK integration, card data is captured by Cybersource's PCI-certified infrastructure rather than the merchant's server, reducing the merchant's PCI compliance scope to SAQ A (the simplest self-assessment questionnaire). WebApp Nepal does not build NIMB gateway integrations that pass raw card data through merchant servers, ensuring merchants operate within the appropriate PCI DSS scope. ### Which Nepal businesses should use the NIMB Cybersource gateway? NIMB Cybersource gateway is most appropriate for: trekking agencies and adventure operators accepting international tour deposits from European, North American, and Australian clients; hotels and resorts taking direct booking pre-payments from international guests; export e-commerce businesses (handicrafts, Pashmina, Thangka, jewellery) serving international buyers; educational institutions collecting fees from international or non-Nepali students; and NGOs accepting card donations from international individual supporters. Any Nepal business that needs to accept Visa or Mastercard from international buyers while settling in NPR within Nepal's banking system should evaluate NIMB gateway. ### How much does NIMB Cybersource gateway integration cost? NIMB Cybersource gateway integration pricing at WebApp Nepal: Secure Acceptance Hosted Checkout (redirect flow) costs NPR 35,000 to NPR 55,000. Web SDK integration with embedded card collection and admin refund panel costs NPR 55,000 to NPR 90,000. REST API integration for complex flows (pre-authorisation, subscription tokenisation) is scoped individually from NPR 80,000 to NPR 1,60,000. Integration as part of a new trekking, hotel, or e-commerce website is included within the full project scope. All integrations include 3DS configuration, transaction logging, sandbox testing, and security review. ### Can the NIMB gateway accept payments in USD and settle in NPR? Yes. This is one of the gateway's key features for Nepal export and tourism businesses. International customers pay in their card's billing currency (USD, GBP, EUR, AUD, etc.) - the amount is charged to their card in their currency. NIMB converts the payment to NPR at the prevailing exchange rate and settles the NPR amount (net of MDR) to the merchant's NIMB current account. This currency conversion at the bank level, with NPR settlement, is what makes NIMB gateway compliant with NRB's foreign exchange framework for Nepal businesses earning from international customers. ### Does WebApp Nepal test NIMB gateway integrations before going live? Yes. All NIMB Cybersource gateway integrations are fully tested in Cybersource's sandbox environment before production credentials are used. Sandbox testing covers: successful Visa and Mastercard transactions, declined card scenarios (insufficient funds, card blocked), 3D Secure challenge flows, result signature validation with both valid and tampered parameters, refund processing, and idempotency for duplicate request handling. The full test scenario set is documented and client-reviewed before the integration is switched to production NIMB merchant credentials. ### What is the difference between Cybersource Secure Acceptance Hosted Checkout and the Web SDK? Hosted Checkout redirects the customer to a Cybersource-hosted payment page - the customer leaves the merchant site temporarily to enter card details, then is redirected back. Simple to implement, lowest PCI burden, but involves a visible redirect that some merchants find disruptive to their checkout flow. Web SDK embeds a Cybersource-hosted iframe within the merchant's own page - the customer stays on the merchant's site throughout checkout. Card data is still captured by Cybersource's PCI-certified infrastructure (not the merchant page), but the visual experience is seamless. WebApp Nepal recommends Web SDK for hotel and trekking booking platforms where checkout UX continuity is important. ### How does NIMB gateway handle failed or declined transactions? Cybersource returns a response code for every transaction indicating the result: approved, declined (with a reason code), or error. WebApp Nepal's integrations map these response codes to user-facing messages: a soft decline (insufficient funds, card temporarily unavailable) prompts the customer to retry with a different card or contact their bank; a hard decline (card blocked, suspected fraud) advises the customer to use an alternative payment method. Order status remains as 'pending payment' for declines - the order is not cancelled automatically to allow retry attempts. Declined transaction events are logged with the full Cybersource response for merchant review. ### How do I get started with NIMB Cybersource payment gateway integration? Two processes run in parallel: (1) Apply for a NIMB merchant current account - contact NIMB's merchant banking team with your business registration documents, PAN certificate, and completed merchant application form. NIMB issues merchant credentials after KYC review (one to three weeks). (2) Contact WebApp Nepal to scope the technical integration - we assess your website or application, advise on the appropriate Cybersource integration method (hosted checkout vs Web SDK vs REST API), and produce a proposal with timeline and NPR pricing. Development begins when merchant credentials are available; sandbox credentials can often be obtained earlier than production credentials to allow development to proceed before the full merchant account is approved.