The memo line sits in the bottom left corner of a check, usually labeled "Memo" or "For." It's optional and isn't used by the bank to process the payment — it's there purely for your records and the recipient's.
What to put on it
- An invoice or order number, so the recipient knows what the payment covers
- An account number, if you're paying a biller like a utility company
- A short note for your own bookkeeping, like "March rent" or "Reimbursement"
Avoid writing sensitive information here, like a full account or Social Security number — the memo line is visible to anyone who handles the check as it moves through the banking system.