Making Sense of the Federal Reserve
The Federal Reserve Banks and Currency
Did you know that Federal Reserve Banks place the currency you use to make purchases into circulation? Each bill has a number and a letter that denote the Federal Reserve Bank that accounts for that particular bill. For example, a bill with the number 8 will have the letter H (the eighth letter in the alphabet), which means it appears on the balance sheet of the Federal Reserve Bank of St. Louis.
For the recently redesigned $5, $10, $20, $50, and $100 bills, the letter and number that identify the Federal Reserve Bank are beneath the left serial number on the face of the bill.