Offering a smooth and secure UPI payments in today’s world can make a big difference to your customers’ checkout experience. To enable this, you need a dependable payment gateway that connects your website with India’s real-time payment network.
This guide walks you through the complete process of UPI payment gateway integration—from choosing the right provider to adding the payment gateway API on your site. You’ll also learn how online payment platforms simplify UPI transactions and how to make the setup safe, efficient, and user-friendly.
| Table of Contents Why Integrate a UPI Payment Gateway? Step-by-Step Guide to UPI Payment Gateway Integration UPI Integration Flow with PayU Conclusion |
Why Integrate a UPI Payment Gateway?
Before you dive into integration, understand why a UPI payment gateway is crucial:
- UPI is one of the fastest-growing payment methods in India. It offers instant peer-to-merchant transfers without needing card details.
- Customers expect UPI options on checkout pages. Without a UPI payment gateway for website you may lose conversions.
- UPI fees tend to be lower compared to card processing fees. Using UPI in your payment gateway integration can reduce cost and friction.
- It improves trust: many users are comfortable paying via UPI; offering it makes your site feel modern and user-friendly.
So when you ask how to integrate the UPI payment gateway, you’re improving your checkout flow, reducing drop-offs and enhancing your business’s payment capabilities.
Step-by-Step Guide to UPI Payment Gateway Integration
Here is how you can integrate a UPI payment gateway into your website. These steps apply generally; specific code or endpoints depend on the provider you choose.
Step 1: Choose Your UPI Payment Gateway Provider
First, select a payment gateway for website that supports UPI. Examples: PayU, PhonePe, Cashfree. Consider the following:
- Does it support UPI flows you want (Web Collect / Intent / QR)?
- What are its transaction fees, settlement time, documentation quality?
- Does it provide SDKs or libraries, or only raw API?
- Does it support your tech stack (backend language / framework / frontend tech)?
Step 2: Register & Complete KYC / Onboarding
You need to create a merchant account with the gateway provider and complete KYC. The process generally includes:
- Submitting company information: registration papers, GST/PAN details, address proof.
- Filling merchant-profile forms (business vertical, expected transaction volume).
- Getting approval from the gateway.
When this is done, you are issued credentials such as API keys (or client ID / secret), sandbox / production keys. Without these, you cannot proceed with the payment gateway api integration.
Step 3: Choose Integration Mode & Obtain API / SDK Access
You will receive developer-access:
- API or payment gateway api endpoints for your server/backend
- Or SDK / plugin / library (for backend / mobile / client)
- Sandbox environment (test keys) and production environment
Decide which UPI integration flow you want:
- Web-Collect (or payment-collect form on web)
- UPI Intent Flow (redirecting or opening UPI app)
- QR Code flow (especially web-QR or dynamic QR)
Make sure your provider supports that flow via its SDK or API.
Step 4: Integrate Frontend / Backend (API / SDK Implementation)
This is the core of payment gateway integration. Here is a generic flow you might follow:
Create Payment Request (Backend)
○ You build an API-call from your server to the payment gateway’s “initiate payment” endpoint.
○ Pass parameters like merchant identifier, amount, order id, currency, callback / redirect URL.
○ The server will authorize / generate a payment token; sometimes compute signature/checksum.
Render UPI Button / Form on Frontend
○ On your website’s checkout page you show “Pay with UPI” or similar.
○ Depending on flow, you may ask user to enter UPI ID, or open UPI app via intent, or generate and display QR code.
Handle User’s UPI Action
○ If user selects Intent flow, your frontend triggers redirect or opens UPI app with payment details.
○ If using Web Collect, you might display a form where user enters UPI ID and confirms.
○ For QR-based flow, you show a dynamically generated QR (from gateway), user scans via mobile app.
Callback / Redirect Handling (Backend)
○ After payment, gateway sends response (success / failure / pending) to your backend via callback URL.
○ Your backend verifies the payment status (via API verification endpoint).
○ Update order status in your database; display status to user.
Testing in Sandbox Mode
○ Before going live, run test transactions via sandbox keys.
○ Validate behavior: success, failure, timeout, usability.
○ Check error handling, logging, security.
Go Live with Production Keys
○ Replace sandbox keys with production ones.
○ Ensure HTTPS, secure your credentials.
○ Monitor first real transactions, check logs and reconciliation.
Many payment gateway API reference guides provide sample code in languages like JavaScript, Python, PHP, etc. You can adapt that in your backend.
Step 5: Post-Integration Activities & Monitoring
After you have integrated the UPI payment gateway:
● Enable logs and monitoring for transaction failures or timeouts
● Make sure refunds or cancellations (if allowed) work correctly
● Keep your dashboard / reconciliation tool in sync with your backend records
● Watch for user complaints about payment failures or delays
● Ensure compliance or certificate compliance (if required by your provider)
Test real-world load and check that settlement times and fund transfers reach your bank account as promised by your gateway.
UPI Integration Flow with PayU
Here’s a simplified walkthrough of how UPI integration works using PayU’s payment gateway:
Sign Up and Onboard
You begin by creating a merchant account with PayU, completing the KYC process, and obtaining your API Key and Salt (used for authentication and encryption).
Select Your UPI Flow
Choose the integration type that fits your business, such as Intent Flow, Collect Request, or QR Code Payment. Each flow defines how your customer interacts with the UPI payment option on your site.
Initiate Payment Request from Backend
From your server, call PayU’s /payment or initiate Transaction API, passing essential details like order ID, amount, currency, customer name, and redirect URLs.
PayU will generate a transaction token or hash, which is required for securely initiating the payment.
Add UPI Payment Option on Checkout Page
On your checkout page, display a “Pay with UPI” button. When clicked, it triggers the selected UPI flow—either opening the customer’s UPI app (Intent), sending a collect request, or showing a QR code generated by PayU.
Handle Payment Callback and Verification
Once the user has authorized payment in their UPI app, PayU sends a response or callback to your backend confirming the transaction status. Then it’s the job of your backend to verify the payment details by calling PayU’s verification API and update the order status accordingly.
Testing and Go-Live
Run test transactions using PayU’s sandbox environment to confirm that all flows work properly. Once tested, switch to your live credentials and start accepting real payments.
You can monitor payments, refunds, and settlements through the PayU merchant dashboard.
This setup follows the standard payment gateway integration approach used across most providers, with PayU offering flexible options for UPI and other payment methods through its payment gateway API.
Conclusion
Integrating a UPI payment gateway into your website can significantly improve your checkout experience, reduce friction, and help convert more customers. By following the steps above, namely choosing a provider, completing onboarding, integrating via API or SDK, testing carefully, and monitoring post-go-live, you’ll have a stable and secure UPI payment flow.
