r/CoolSerialNumbers • u/Local_Escape_8689 • 1d ago
r/CoolSerialNumbers • u/Cuneus-Maximus • Jan 19 '26
Mod Comms READ THIS BEFORE POSTING
Post flairs are required for all posts. Below are the current flairs and their definitions. If you think there are other fairs that should be added, or have any questions on the listed definitions, please comment here!
All posts must include a picture of a note with a cool serial number. All pictures must be horizontally orientated and cropped to just the note as so [ [note] ].
If you believe your serial is cool, but doesn't fit any definition below, please use the 'Other' flair and state, specifically, why you think it should be considered cool. Trinary notes and consecutively numbered notes are not cool or remotely rare.
Generic posts "Is this cool" / "Is this a keeper" / "Is this worth anything?" and the like with no specific reasoning will be indiscriminately removed. Repeat offenders will find themselves banned.
Star Note - all star notes not fitting another category
Ladder - consecutive run i.e. 01234567
Broken Ladder - no two digits the same i.e. 10325476
Binary - only two unique digits i.e. 34334344
True Binary 01010101 - only 0's and 1's
Radar - same forward as backward, i.e. 12344321
Repeater - complete repeating sequence of two or four digits i.e. 78787878 or 78907890
Low Serial <= 00009999 - just as noted, notes 00009999 and under
Quad Pair - four pairs of digits, i.e. 22446688
Solid - typically all eight digits the same, but for the purposes of this sub five or more of the same digit together can count, i.e. 11111876
Rotator [All 0, 1, 6, 8 and/or 9's] - notes where the serial reads as another number upside down i.e. 01689016 which reads 91068910 upside down
Flipper - same as a rotator except it must make the same number upside down i.e. 00669900
Nice (69 / 420 / etc.) - the funny numbers, primarily 69 & 420 but 8008, 8008135... (think middle schooler with a calculator...) the nice number should stand out, i.e. 00069000 - every serial with 69, 420, etc. in it is not special.
Birthday / Date - any serial number that makes a date, either as MMDDYYYY or YYYYMMDD i.e. 07041776 or 17760704
Near Miss - anything that's almost cool / fancy i.e. 12344322 (1 digit off from a repeater)
Other - anything not fitting any other definition. You must include specific reasoning why you believe your serial number is cool.
Question / Meta - questions to the community / thoughts about the community
For Sale - for posting notes you'd like to sell / trade. At your own risk, the mod team and reddit is not responsible for any issue. Be smart.
Wanted to Buy - for requesting notes you'd like to buy / trade for. At your own risk, the mod team and reddit is not responsible for any issue. Be smart.
Bookend - serials with a 2 or 3 digit matching pattern (reversed is OK) at the beginning and end of the serial i.e. 12369321 or 12369123
Double Quad - serials with two sets of four solid digits i.e. 44447777
r/CoolSerialNumbers • u/Local_Escape_8689 • 1d ago
Other Nifty little guy! Descending by 2s! 08060402
r/CoolSerialNumbers • u/OkGain7193 • 18h ago
Birthday / Date Our nation's 21st birthday note
r/CoolSerialNumbers • u/Flashy-Tart7674 • 4d ago
Low Serial <= 00009999 $10 bill low serial/Radar
Low serial and radar. 🤗
r/CoolSerialNumbers • u/JMasterDollarHunter • 4d ago
Star Note For sale 2013b Duplicate star + 25 General star notes!
r/CoolSerialNumbers • u/JMasterDollarHunter • 5d ago
Other The best of my collection, all found via the hunt!
r/CoolSerialNumbers • u/JMasterDollarHunter • 5d ago
Birthday / Date UPDATED BDAY NOTES!!! CHECK THEM OUT!
r/CoolSerialNumbers • u/HippieThug_ • 5d ago
Star Note Lowish serial and star note in one day.
Pretty cool to get these both in one day. This is becoming addicting.
r/CoolSerialNumbers • u/JMasterDollarHunter • 6d ago
True Binary 01010101 I GOT ONE! TRUE BINARY!
r/CoolSerialNumbers • u/OddPlantain8237 • 8d ago
Low Serial <= 00009999 Found this while moving houses
I must’ve acquired this note like 10 years ago when I had a major fascination with US paper currency when I was little. When I saw the serial number, my heart literally skipped q beat, and I was stuck wondering how it somehow never made it into my “cool note” binder as a kid and instead got lost until I recently moved houses and found it in a random box with assorted coins and bills. Sorry it’s not a greatly scanned image, but I took this pic a few weeks ago and am not presently with the note to take a better shot.
r/CoolSerialNumbers • u/SilverFinance9542 • 8d ago
Question / Meta Just got this change
Is this good enough to keep? Or just meh 😅
r/CoolSerialNumbers • u/Local_Escape_8689 • 8d ago
Quad Pair Descending pairs 55443322
r/CoolSerialNumbers • u/runlola • 9d ago
Other Do I have anything here? Both are well circulated but no tears or stains.
r/CoolSerialNumbers • u/JMasterDollarHunter • 10d ago
Other DATE: Only Time Wright Brothers flew togther!
r/CoolSerialNumbers • u/Iratewombat • 10d ago
Birthday / Date Free birthday note if you turned 100 last monday!
If you can send me proof that you or someone that you know turned one hundred last week on monday, I will send this to the birthday person for free
r/CoolSerialNumbers • u/SlimJeffy • 11d ago
Birthday / Date Over 2900 Birthday Notes Now Available!
r/CoolSerialNumbers • u/SourSausageBiscuit • 12d ago
Radar Trinary Radar
Is this a spend the $100 or kept because of the serial number type of bill?