To write the amount on a check, put the digits in the small box next to the printed dollar sign (for example, 1,250.00), then on the long line below “Pay to the order of” spell out the whole dollars in words, add “and,” write the cents as a fraction over 100, and draw a line to the printed word “Dollars.” So $236.79 becomes “Two hundred thirty-six and 79/100————.” The written line is what the bank legally treats as the amount, so it deserves the most care.
The Numeric Box
The box on the right side of the check, next to the pre-printed dollar sign, holds the amount in digits. Use a decimal point to separate dollars from cents, and include both cent digits even when the amount is round. Write $1,250.00, not $1,250. Start your first digit as close to the printed dollar sign as you can, so no one can slip an extra number in front.
The Written Amount Line
The long line under the payee is where you spell the same amount out. Banks treat this field as the controlling one, so the conventions matter:
- Spell the whole-dollar portion in words. For $142, write “One hundred forty-two.”
- Use “and” once, and only at the boundary between dollars and cents. Do not write “One hundred and forty-two.”
- Write the cents as a number over 100. Seventy-five cents becomes 75/100. No cents becomes 00/100.
- Hyphenate compound numbers from twenty-one through ninety-nine: “forty-two,” “sixty-seven,” “eighty-nine.”
- After the last character, draw a solid horizontal line across any remaining space to the printed word “Dollars.” That line closes the field so nothing can be added later.
A check for $236.79 reads: “Two hundred thirty-six and 79/100” with a line running to “Dollars.”
Round Dollar Amounts
Even with no cents owed, account for the fractional portion. A $500 check reads “Five hundred and 00/100.” The 00/100 shows that no cents are due and keeps anyone from writing a value in later.
Amounts Over One Thousand
Spell each grouping in order. A check for $2,575.50 reads: “Two thousand five hundred seventy-five and 50/100.” A comma after “thousand” is optional. Hyphens on compound numbers stay put no matter how large the total is; “seventy-five” is still “seventy-five.”
Amounts Under One Dollar
Checks for less than a dollar are unusual but valid. Write “Zero and” followed by the fraction, such as “Zero and 45/100.” In the numeric box, enter 0.45. You can skip the “Zero and,” but writing it out leaves no doubt about your intent.
Single-Digit Cents
When the cent amount is below ten, use a leading zero so the fraction can’t be misread. For $300.05, write the cents as 05/100, not 5/100. Without the zero, a five is easy to turn into a fifty.
If the Words and the Numbers Don’t Match
Sometimes the box and the line disagree. Under the Uniform Commercial Code, when a check contains contradictory terms, the words control and override the numbers.1Cornell Law School. Uniform Commercial Code 3-114 – Contradictory Terms of Instrument If your box says $50.00 but the line says “Fifty-five and 00/100,” the bank will pay fifty-five dollars. Words are harder to alter than digits and are treated as the more deliberate expression of what you meant.
That is why the written line deserves the closer read before you sign. Catch a mismatch and you do not fix it by squeezing in changes; you void the check and start over.
Fill the Space So No One Else Can
Check fraud has risen sharply, with regulators tracking roughly 682,000 check-fraud-related suspicious activity reports in 2024, nearly double the volume of a few years earlier. Two habits tied to how you write the amount make your check much harder to alter.
Start every field as far to the left as possible. Then draw a thick line through any leftover space after your written amount. Empty space is what lets a criminal add a digit or a word that inflates the check.
Use a gel ink pen, preferably black. Gel ink bonds with paper fibers more tightly than standard ballpoint ink, which resists “check washing,” where chemicals are used to dissolve the ink and rewrite the payee or amount. Attempts to wash gel ink typically leave visible damage on the paper.
Voiding a Check You Wrote Wrong
If you make a mistake on the amount, whether in the box, on the line, or between the two, do not scratch it out and write over it. Banks may refuse altered checks, and corrections can look like tampering. Write “VOID” in large letters across the front, covering the payee line, both amount fields, and the signature area. Note the voided check number in your register, then write a new one. Keep the voided check until you no longer need it for your records, and shred it when you do; it still shows your routing and account numbers.
One boundary worth knowing: writing the amount is only part of a valid check. Under the UCC, no one is liable on a negotiable instrument unless they have signed it or authorized a signature on their behalf,2Cornell Law School. Uniform Commercial Code 3-401 – Signature so a perfectly written amount on an unsigned check still does nothing.