Bezahlcode

Back in 2012, I proposed a “pay:” URL scheme, which looks like this:

pay:amount=57.65;​currency=EUR;​i=FR76.4100.4133.7601.0505.1161.123;​order=ANM11-1210;​name=Dupont+%26+Cie

or with abbreviated syntax:

pay:a=57.65;​c=EUR;​i=FR7641004133760105051161123;​o=ANM11-1210;​n=Dupont+%26+Cie

Some shops in Germany now support a similar URL scheme, which looks like this:

bank://singlepaymentsepa?name=Dupont+%26_Cie​&reason=ANM11-1210​&iban=FR7641004133760105051161123​&bic=BNPAFRPPXXX​&amount=57,65

According to the specification (in German), the “bank:” scheme was invented in 2010 at German company Stoeger IT. The Web site explaining the system has been online since 2011.

My pay scheme and the bank scheme are obviously very similar, but there are some interesting differences:

• The bank scheme requires the amount to be written with a comma instead of a period before the decimals: 32,10 rather than 32.10. That may lead to some bugs, because programmers are used to the English style. ☺
• The BIC (Bank Identification Code) is required. One would think the IBAN on its own is sufficient, but the BIC may be a way to verify that the IBAN is correct.
• The bank scheme starts with “//keyword?” to indicate the type of transaction. Apart from single payments, there are also periodic payments (“bank://periodicsinglepaymentsepa?…” with parameters for start/end date and frequency in weeks/months) and contact information (“bank://contact_v2?…”), which omits the amount to provide just a name and account number.
• The bank scheme allows to omit the currency, in which case EUR (€) is assumed.
• The bank scheme is designed to fit in a QR code and thus has upper limits on the size of each field. In particular, the free text field is limited to 140 character. Presumably, those are Unicode characters, not bytes. After encoding as UTF-8 and percent-escaping, this may indeed get close to the size of the largest QR code (version 40), which can hold some 2K bytes. I mentioned QR codes as a way to display short “pay:” URLs, but I didn't require all URLs to be short.
• The bank scheme doesn't have room for a URL (e.g., to link back to an online purchase, where you can see if the seller has already received your money).

The specification for the bank scheme doens't talk about protecting against double payments, but presumably the software and/or the user's bank should warn the user when the same combination of IBAN, amount and payment reason are seen twice.

The reason field (called order number in my scheme) is free text. It's up to the seller to put something there that is unique enough to recognize a payment.

Both my pay scheme and the bank scheme rely on payment into a bank account. There is no provision for paying cash (with bitcoins, e.g.)

(Thanks to Christian Weiske for alerting me to the BezahlCode.)