How UPI Payment QR Codes Work: Specifications, URL Parameters, and Storefront Setup

The Architecture Behind Seamless Digital Payments

Across millions of retail counters, cafés, and market stalls, printed UPI QR codes have revolutionized how transactions take place. A customer pulls out their phone, points the camera at a counter standee, and their favorite payment app launches instantly with the merchant details already filled in.

The underlying technology is surprisingly elegant. Developed by the National Payments Corporation of India, UPI QR codes follow an open, standardized URI deep-link specification that any compliant payment app can read and process.

Deconstructing the UPI Payment Link

When a smartphone camera scans a merchant code, it reads a structured URI string that looks something like this:

upi://pay?pa=storename@icici&pn=Heritage%20Books&cu=INR&tn=Order%20Payment

Each query parameter handles a specific operational role:

The payee address parameter represents the Virtual Payment Address of the business or account holder. This is where the funds will be deposited.

The payee name parameter specifies the registered business name or individual account name. This is what the customer sees on their confirmation screen before approving the payment.

The currency parameter is set to INR for Indian Rupee transactions. Additional optional parameters can include transaction reference IDs for automated bookkeeping or pre-filled amounts for fixed-price invoices.

Static Counter Signs vs. Dynamic Bill Codes

Merchants typically deploy UPI codes in one of two configurations:

A static counter standee contains only the merchant ID and name, leaving the payment amount blank. When customers scan the code, their phone prompts them to enter the exact bill amount, authenticate with their PIN, and display the confirmation screen to the cashier. Because these codes contain no fixed invoice amount, you can print them once on durable acrylic or metal and use them indefinitely.

Dynamic invoicing codes, on the other hand, include a pre-set amount and invoice number. These are commonly printed directly onto customer checkout receipts or displayed on digital point-of-sale screens. The customer scans the receipt and confirms the pre-calculated total without having to type numbers manually.

Print Recommendations for Checkout Counters

For point-of-sale counter standees viewed from thirty to fifty centimeters away, print your code at least 50 mm wide. If your design includes your store monogram or brand logo in the center, generate the code with High error correction so the center artwork does not interfere with scanning under dim indoor lighting.