On occasion, a bill shows up that has a small star in place of the final letter in the serial, and many early issues carried the star in front of the serial number. Altogether, there are a possible 2,499,999,975 serial numbers for each bank.
The final letter is used to raise the number of possible bills beyond 99,999,999.Using these digits alone, there would be a possible 99,999,999 bills issued per bank. This number increases sequentially as each bill is printed. The eight numerical digits that follow represent a unique ID number.Find 2017 20 Dollar Bill Error Miscut Misaligned Bank Note and more at collectors. As there are 12 Federal Reserve Banks, this letter can range from A to L, with A representing Boston and L representing San Francisco. Say you find a dollar bill that has the serial number 12345678, thats going. The second letter (or first, if you're looking at an old-style bill) represents the district of the Federal Reserve Bank that your bill was issued from.You can also find the series of the bill printed directly to the bottom-right of the portrait. This begins with A, and moves through the alphabet each time a new series is needed (for example, each time there is a new secretary of the treasury, the bill design changes because the secretary's signature is on all currency). The series indicates the year in which the design of the bill was approved for production.
