Paper Money Errors to Look For

Paper money errors are less common than coin errors, but they exist and can be valuable. U.S. currency goes through multiple printing stages, and mistakes can happen at any point — from ink application to final cutting. Here is what to look for and how to tell a real error from damage.

Common Paper Money Error Types

Cutting Errors

The most common paper money error. Printed sheets are cut into individual notes at the end of production. When the cutting is misaligned, bills come out with uneven margins — one side wider than the other, or the design shifted so borders are noticeably different. Severe cutting errors where you can see part of the adjacent note's design are especially valuable.

Ink Errors

• Ink smears — Excess ink dragged across the face of the bill during printing.
• Insufficient inking — Part of the design printed too lightly or missing entirely because the ink supply ran low.
• Offset printing — Design from one side of the bill transfers onto the other side as a ghost image.

Foldover Errors

A foldover happens when the paper creases or folds before going through the press. The result is a bill with part of the design missing (where the paper was folded over) and sometimes printing on the wrong area. When the fold is opened, you see a blank white section and a misplaced chunk of design. This is one of the more dramatic and collectible errors.

Missing Print Areas

Sometimes an entire printing stage is skipped. U.S. currency is printed in multiple passes: the back is printed first, then the front face, then the serial numbers and seals are added. If a stage is missed, you get a bill with a blank back, missing serial numbers, or no Treasury seal. These are rare and valuable.

Misaligned Overprint

The serial numbers, Treasury seal, and Federal Reserve seal are printed in a separate pass from the main design. If this overprint pass is misaligned, the serial numbers and seals appear shifted to one side or at an angle relative to the rest of the bill.

Inverted Overprint

The sheet was fed into the overprint press upside down, so serial numbers and seals appear on the wrong end of the bill. These are rare and command strong premiums.

Obstruction Errors

A piece of paper, tape, or other material got between the printing plate and the note during production. The obstructed area is blank, and sometimes the obstruction itself is still attached to the bill.

Damage vs. Error

Just like with coins, not every odd-looking bill is an error. Paper money can be altered, washed, or damaged after it enters circulation.

• Washed or bleached bills — Criminals sometimes wash lower denomination bills and reprint them as higher denominations. These are counterfeit, not errors.
• Tape, writing, and stamps — Marks added after printing are damage, not errors.
• Torn or repaired bills — Physical damage from use is not a manufacturing error.
• Faded ink — Exposure to sunlight or chemicals fades ink over time. This is environmental damage.

What to Check on Any Bill

1. Margins — Are they even on all sides? Uneven margins may indicate a cutting error.
2. Serial numbers — Are they straight and properly positioned? Shifted or missing serial numbers are errors.
3. Both sides printed? — Hold the bill up to light. If one side is blank or partially blank, that is a missing print error.
4. Ghost images — Look for faint mirror images of the opposite side, which indicate offset printing errors.
5. Paper consistency — Genuine U.S. currency paper contains red and blue security fibers. If the paper looks wrong, the bill may be counterfeit rather than an error.