The UPI QR code format, parameter by parameter

The link

upi://pay?pa=merchant@okhdfcbank&pn=Chai%20Point&am=120.00&cu=INR&tn=Table%207&tr=ORD10432&mc=5812

Every parameter

Param	Name	Required	Constraint
pa	Payee address (VPA)	yes	name@handle, 2–256 chars before @, 2–64 letters after
pn	Payee name	yes	Shown on the payer's confirmation screen
am	Amount	no	Up to 2 decimal places
cu	Currency	effectively yes	INR
tn	Transaction note	no	Keep under ~25 chars
tr	Transaction reference	no	1–35 chars, [A-Za-z0-9.-]
mc	Merchant category code	no	Exactly 4 digits, ISO 18245
mode	Mode	no	02 for merchant-presented static
sign	Signature	no	Only for PSP-issued signed codes
url	Invoice URL	no	Rarely honoured

Why the confirmation screen matters

pn is what the payer sees before they authorise. It is not decoration — it is the only fraud check most customers will ever perform. If a fraudster pastes their own code over yours, the mismatch between the printed business name and the name in the app is what gives it away.

Print your business name large, right next to the code, matching pn exactly.

Merchant category codes

mc affects more than reporting. Some issuers apply different limits, interchange or rewards by category, and certain UPI-Lite and offline flows are gated on it.

MCC	Category
5411	Grocery stores
5812	Restaurants
5814	Fast food
5912	Pharmacies
5541	Service stations
8220	Education
4121	Taxi and rideshare
8398	Charitable organisations

If your PSP issued your merchant VPA, use the MCC they assigned rather than choosing one.

Encoding notes

• The payload is a URI, so every value must be percent-encoded. A space in pn becomes %20; an ampersand becomes %26. Unencoded, the parameter list breaks at the first space.
• Keep tn short. Each character adds modules, and a long note can push the code up two versions, shrinking every module at the printed size.
• UseQR validates the VPA pattern, the two-decimal amount, the 4-digit MCC and the 35-character reference before generating — the constraints NPCI actually imposes.

One code, every app

There is no such thing as a "Google Pay QR code" or a "PhonePe QR code" that another app cannot read. NPCI standardised the format precisely so a merchant needs one standee. Anyone selling per-app codes is selling nothing.

FAQ

What are the required parameters in a UPI QR code?

pa (the payee VPA) and pn (the payee name). Everything else — amount, note, reference, merchant category — is optional, and cu=INR is conventionally always present.

Do I need separate QR codes for Google Pay and PhonePe?

No. NPCI standardised the upi://pay format, so one code works in every UPI app and every bank app.

What is the mc parameter?

The four-digit ISO 18245 merchant category code. Some issuers apply different limits or rewards by category, and some offline flows depend on it.

Why does my UPI QR code show the wrong name?

The pn parameter is what the app displays. If it differs from your business name, either the code was generated with the wrong value, or someone has pasted a different code over yours.