Most of us handle $1 bills without a second thought. But some of these everyday bills could be worth thousands — all because of their serial numbers.

Currency collectors seek out “fancy serial numbers”, which feature rare or unusual patterns. When combined with a bill in good condition, these can dramatically increase its value.

Highly sought-after types include:

• Low serial numbers (00000001–00000100)

• Repeating patterns like 88888888 or 12344321

• “Ladder” numbers, such as 12345678

• “Radar” numbers, which read the same forward and backward (e.g., 01133110)

• “Birthday” serials that resemble dates (e.g., 07041876)

Collectors also look for “Star notes”, which are printed to replace damaged bills. These have a star (*) at the end of the serial number and can be more valuable depending on rarity.

Among the rarest are “binary repeaters” — numbers with only two digits in a repeating pattern, like 01010101 or 29292929. In excellent condition, these can be worth $5,000 or more.

So, before you toss that crumpled dollar into a tip jar, take a closer look. You might be holding a collector’s dream — hiding in plain sight.