EMVCo merchant QR

The EMVCo QR Code Specification is the TLV-encoded format that sits underneath most national mobile-payment schemes, PIX (Brazil), PromptPay (Thailand), UPI (India), SGQR (Singapore), DuitNow (Malaysia), BPS PayNow (Singapore), and many others. Understanding the EMVCo base format means understanding a dozen regional derivatives at once.

Canonical spec:EMV QR Code Specification for Payment Systems, Merchant Presented Mode v1.1 (2020) and Consumer Presented Mode v1.1 (2020).
Encoding: TLV (Tag-Length-Value) with 2-digit tags, 2-digit lengths, variable value. CRC16-CCITT trailer for integrity.

Merchant Presented vs Consumer Presented

MPM (Merchant Presented Mode). Static or dynamic QR displayed by the merchant. Consumer scans it from their banking/wallet app and authorises the payment. 99% of real-world QR payments use MPM.
CPM (Consumer Presented Mode). Consumer's app generates a short-lived QR (typically 30–60 seconds); merchant scans it. Less common; used where consumer connectivity is unreliable (rural India pre-UPI ubiquity, some MRT/transit systems).

MPM structure

MPM payload is a flat sequence of TLV records terminated by a CRC:

Tag	Name	Length	Notes
`00`	Payload format indicator	2	Always `01`.
`01`	Point of initiation method	2	`11` static / `12` dynamic.
`02`–`51`	Merchant account information	variable	Scheme-specific. Each scheme reserves its own tag: PIX uses `26`, UPI uses `26` too, SGQR uses `51`.
`52`	Merchant Category Code (MCC)	4	ISO 18245 4-digit code. See table below.
`53`	Transaction currency	3	ISO 4217 numeric. `840`=USD, `978`=EUR, `356`=INR, `986`=BRL, `764`=THB.
`54`	Transaction amount	variable	Decimal as string. Omit for static amount-at-scan QRs.
`58`	Country code	2	ISO 3166 alpha-2.
`59`	Merchant name	variable	Max 25 chars per spec; many schemes relax this.
`60`	Merchant city	variable	Max 15 chars.
`62`	Additional data field template	variable	Bill reference, loyalty, terminal ID.
`63`	CRC	4	CRC16-CCITT over everything before this tag (including the tag itself, length 04, minus the 4-digit value).

Regional schemes that derive from EMVCo

Scheme	Country	Merchant account tag	Notes
PIX	Brazil	`26`	Brazilian Central Bank instant-payment scheme. Adds CPF/CNPJ/email/phone PIX keys as sub-TLVs under tag 26.
PromptPay	Thailand	`29` / `30`	Uses `29` for national ID / tax ID and `30` for mobile number.
UPI	India	`26`	Same EMVCo base with UPI-specific sub-TLVs (VPA, payee name).
SGQR	Singapore	`51`	Unified QR that encodes multiple payment rails (PayNow, NETS, UOB Pay) simultaneously.
DuitNow	Malaysia	`27`	PayNet's national instant payment scheme.
FPS	Hong Kong	`27`	Faster Payment System by HKICL.
JPQR	Japan	`50`	METI-backed unified Japanese QR standard.

Common MCC codes

MCC	Merchant category
`5411`	Grocery stores, supermarkets
`5812`	Eating places, restaurants
`5814`	Fast-food restaurants
`5999`	Miscellaneous retail
`7230`	Beauty / barber shops
`8011`	Doctors
`8398`	Charitable / social service organisations
`0000`	Unknown / placeholder (spec allows this)

Canonical test vectors

Case	Inputs	Expected TLV head
Static MPM, USD, no amount	`merchant=Acme Corp city=LAS VEGAS country=US currency=840 mcc=5999`	`00020101021152045999...53037405802US5909Acme Corp6009LAS VEGAS`
Dynamic MPM, EUR, amount 25.00	(same) `amount=25.00`	Starts `000201010212` (POI method 12 = dynamic), includes `540525.00`.
Restaurant bill, INR 250, MCC 5812	`merchant=Spice House city=MUMBAI country=IN currency=356 mcc=5812 amount=250`	MCC field: `52045812`. Currency: `5303356`.

Common pitfalls

CRC computed wrong. The CRC16-CCITT is over the ENTIRE payload including tag 63 and length 04, everything up to but not including the 4-digit CRC value. Most bugs come from computing over the payload only or including the CRC value itself.
Length field is 2 digits. Even a 1-character value takes length 01. A 100-character value takes length ??, but wait, EMVCo caps values at 99 chars because length is 2 digits. Longer values need to be split across multiple sub-TLVs.
Currency code is numeric, not alpha. USD is 840, not USD. EUR is 978. BRL is 986. ISO 4217 has both alpha-3 and numeric; EMVCo requires numeric.
Country code is alpha-2. US, IN, BR, TH. ISO 3166-1 alpha-2. Confusingly opposite to the currency-code rule.
Static vs dynamic. If you omit the amount (tag 54), use POI method 11 (static). Static QR + amount field is spec-legal but some apps reject it. Dynamic QR without amount is a spec violation.
Merchant name char limit. Per spec, 25 chars max. Some regional schemes relax this (PIX allows 25, SGQR allows 40). Hand-tune per scheme if you're targeting a specific country.
MCC 0000. The spec permits 0000 as unknown, but many acquirers reject it in settlement. Always prefer a real MCC when you have one.

Scanner compatibility

App / device	Support	Notes
Banking / wallet app	Native	Regional apps in each country (Nubank / UPI apps / TrueMoney / GrabPay) parse the EMVCo payload natively.
iOS Camera	Raw string	Not recognised as payment. User must open their banking app and scan from there.
Android Camera	Raw string	Same, not parsed.
Google Lens	Raw string	Displays decoded text.
Industrial payment terminals	Native	Modern POS scanners include EMVCo parsing in firmware for the regional scheme(s) they support.