How to read the serial number on an Indian banknote
Every note the RBI issues carries a unique number, printed twice on the front: once at the top left, once at the bottom right. On the Mahatma Gandhi (New) Series the digits grow from small to large as you read left to right — that ascending size is itself a security feature. This page is about what the number is made of and what to type when something asks for it.
What the parts of the number mean
A serial looks like 3AB 123456 or 00A 123456. Left to right:
- Prefix — three characters. Either a digit and two letters (3AB) or two digits and a letter (00A). The prefix identifies the print run; every note in a run of 10 lakh shares it.
- Inset letter — sometimes. A small, pale letter printed between the prefix and the number, like 3ABK 123456. It marks the press that printed the note, not the note itself. Twenty letters are used; I, J, O, X, Y and Z never appear. It is not part of the note's identity.
- Star — sometimes. A ★ in the same spot means the note replaced a misprint. See star notes.
- Number — six digits, 000001 to 999999. The last note of a run is the one exception: it is numbered 1000000, seven digits.
The RBI's Indian Currency FAQ covers the number panel and the security features around it.
What to type when a site asks for the serial
Type it as printed and don't worry about the details. We upper-case it, drop spaces and dashes, and ignore the inset letter, because the same note should have one trail whether or not you noticed the tiny letter. If the note has a star, type * where the star sits: 3AB*123456. Pick the denomination from the list; the same prefix and number can exist on a ₹10 and a ₹500, so the value is part of the identity.
Do older notes have the same number format?
The previous Mahatma Gandhi Series (the designs from 2005 onward, without the heritage-site backs) is still legal tender and still turns up, especially ₹10 and ₹20. The number panel follows the same prefix-and-six-digits shape, so those notes track the same way.
Why the number matters
It is the only thing about a note that is unique. Two ₹100 notes are identical in every way except this, which is what makes cash the one mass-produced object in India you can follow from hand to hand. That is the whole idea behind this site.
Holding a note now? Enter its serial and see if anyone has met it before.