When writing a check, you have to specify the amount using numerals (in the box on the right-hand side) as well as words (on the line that says “Pay”). This practice helps to avoid confusion; if it’s difficult to read one section, you can double-check the amount using the other section.

However, sometimes the amounts written on a check do not match. For example, what if a check shows a numeric value of “$100,” but the handwritten amount reads “ten dollars”? Here's what to do in such cases.

Words Prevail Over Numbers

When the amount of a check is unclear, the written words are considered to be the correct amount.﻿﻿ Numbers written out with words are clearer; you still know how much the check is for, even if you can’t make out half of the letters. On the other hand, numerical digits are almost worthless if they’re hard to read. Section 3.114 of the Uniform Commercial Code (UCC), a set of rules for business transactions, dictates how any confusion should be handled:﻿﻿

“If an instrument contains contradictory terms, typewritten terms prevail over printed terms, handwritten terms prevail over both, and words prevail over numbers.”

In fact, on a check, the space where you write the amount is called the "legal line;" the box where you put the digits is called the "courtesy box."﻿﻿

When the Amounts Don't Match

Written words are supposed to trump the numerical digits, but it doesn’t always happen that way. When a check gets deposited, whoever processes the check might not notice that there’s a discrepancy. In some cases, they might only look at the numbers in the courtesy box and process the check for the wrong amount.

It’s easy for this to happen. Think about when you receive a check: do you look at the numbers in the courtesy box, or do you read the amount off the legal line? Most people glance at the courtesy box because it’s faster and easier, and that can apply to busy tellers and ATM operators that handle deposits, too.

It may not be the end of the world if a check is processed based on the numbers in the courtesy box—sometimes that’s the amount that the check writer intended to pay, and what the payee expected. However, it’s not a good idea to use checks when the amounts don’t match. The bank may discover the contradiction and make unwelcome account adjustments later.

What to Do

Whenever a check has contradictory amounts, it’s best to use a different check. It might be a non-issue if you use the check as written, but it’s not worth the risk of dealing with disputes and delays. If you wrote the check, void the check and write a new one. Otherwise, you never know which amount your payee’s bank will process the check for—and there could be negative consequences.

For instance, say you write a check for your mortgage payment, but mistakenly put down two different amounts. If the bank takes out an amount that's less than what's due, you could be penalized for a late mortgage payment, and that could incur fees and even affect your credit score. If the bank takes more than what you intended to send, you risk running low on cash or even overdrawing your checking account, which could incur fees of its own. Plus, you won’t be allowed to reduce your mortgage payment the following month to make up for it. The overage would be applied to the outstanding principal or interest, but you'd still owe the mortgage company your regular payment.

On the other hand, if you're on the receiving end of a check with mismatched numbers, you can't just start over. It may be difficult or even impossible to get another check, but it’s probably worth your time to try. If the check is processed for more than the check writer intended, you could have a very unhappy customer (or friend, or family member) on your hands. If the check is processed for less than you're owed, you could be out of luck unless you can otherwise get the money you’re due.