Why is currency numbered?

Why are currency notes numbered? In the United States an average of 37 Million notes are printed every day and each of them has a unique seriel number. Is it really necessary for the government to number them or could they just KNOW how many they printed. I understand if only a few thousand were issued it would be important to know which debts were outstanding, but with billions? When they are finally removed from circulation by the FED do they sort them by issuing FRB to keep a running number on each Banks debts? Is numbering notes done out of tradition or is there a more logical answer?


Serial numbers help prevent counterfeiting. It’s hard for counterfeiters to print bills with a different serial number on each one. If a counterfeiter tries to get away with printing the same number on a bunch of bills, he will be easier to catch.

Remember that the serial numbers were around long before computers. In the bad old days, to produce a counterfeit bill you needed a “plate” that you ran on a printing press. Making these plates was (and still is) a highly skilled art. Producing a separate plate for each counterfeit bill was not practical. If you made 1,000 counterfeit $100s, the serial number would be the same on all of them. Thus the Secret Service could use the serial number to hone in on counterfeit bills being circulated.

If the plate gets passed to another counterfeiter in another state, the serial number will still be “highlighted” by the Secret Service and will make it easier to track down and catch said crook.

Oh, and Mr_Weasel welcome to the boards!

How about in all the Movies and TV shows were the crooks as for non-sequential or unmarked bills? I can understand them not wanting an ultra-violet dye attached to them or a radioactive tracking agent but could they really be traced by the sequence of the bills?

If a bank robber takes a numerically sequenced stack of bills, yes, he can be tracked, because the police will then know the serial number of every single bill the robber took. When his bills show up, you can trace his location and make it easier to catch him. If the bills are well out of sequence, they won’t know which bills he took, and they can’t trace him by where he uses his money.


It is easier to keep track of how many are printed if they are numbered. For instance bills that don’t pass qa/qc are taken out and replaced with the same number but with a star instead of a letter in the last place. IMHO even though the numbering makes it difficult to counterfeit it was not the original intent. The hollywood references also make this very suspect - Who looks at serial numbers anyway? - unless you are playing liars poker!

BTW visit the Bureau of Engraving next time you are in DC. The tour isn’t as good as it used to be, but it is pretty neat being next to all that loot.

Why would it be that much more difficult for a counterfeiter to fake serial numbers than it is for the Gov’t to print real ones?

I would also think the serial numbers should be barcoded to be machine-readable. Not that every store would scan your bills, but I can see it being useful in banks, etc.

I don’t know if it applies to american bills (or even current euros) but the on the former french bills, not all the possible numbers were used, but only some of them, based, IIRC, on some code. For instance the bill A 8567212 could be followed by A 8567514 and there was no bill printed with the number 8567213 or 8567326. This of course was used by the central bank to identify more readily counterfeited bills, the counterfeiter not knowing which numbers were corresponding to existing bills.
Of course, I assume they could use the numbers printed on authentic bills (but they would need a bunch of them) or just use random serial numbers (and nobody would have noticed it except for the central bank and perhaps other banks/the police assuming they had access to some database), but I suppose that any trick which would make the work of the counterfeiter a little harder, or help identifying counterfeited bills was used.

Fresh-from-the-bank US$1 bills still have sequential serial numbers…

Don’t all fresh-from-the-bank US bills have sequential serial numbers?

Serially numbering bills makes possible this web site: