If you've seen both terms and wondered whether they mean different things, the short answer is: usually not. In the vast majority of everyday use, "credit memo" and "credit note" refer to the exact same document — one that reduces or cancels an amount owed on a previous invoice.
Where the difference in naming comes from
The variation is mostly regional and industry habit rather than a meaningful functional split. "Credit note" is more common in the UK, much of Europe, and in general business use internationally. "Credit memo" (short for "credit memorandum") shows up more often in the US, particularly in accounting software and formal bookkeeping contexts.
Does it ever mean something different?
In everyday small-business use, no — both describe the same document doing the same job: adjusting a balance after an invoice has already been issued, for a return, an error, a discount, or a cancellation. See our guide on credit notes for what belongs on one and when to issue it.
Some larger accounting systems do draw a technical distinction internally — for instance, treating a "credit memo" as an internal accounting entry and a "credit note" as the customer-facing document derived from it — but this is a system-specific implementation detail, not a difference you need to navigate as a small business issuing one to a client.
Which term should you use?
Use whichever term your clients and your local business conventions expect. If you're not sure, "credit note" is the more broadly understood term internationally, but either is correct — what matters far more than the label is that the document clearly references the original invoice, states the amount and reason, and carries its own number.
The terminology difference is worth knowing so you're not confused seeing both — it's not worth spending time deciding between them.