“My Xero lock date isn’t working” - here’s what’s really going on

Written by an ACA-qualified finance manager · about the author · Last reviewed 1 July 2026

If you set a lock date and a number still changed in a closed period, you’re not doing it wrong - you’ve hit the edge of what lock dates are designed to do. Here’s the gap, and how to close it.

What a Xero lock date actually does

A lock date stops users from adding or editing transactions dated on or before it. There are usually two levels: one for all users, and a second that only advisers/admins can work past. Set them at month-end and they do a real job - they stop the accidental posting into last month.

Why it can still feel like it isn’t working

• Admins can post past it - and lift it. The higher lock level exists precisely so an adviser can make a correction. Anyone with that access can move or remove the lock date, make a change, and set it back. Nothing is flagged.
• It doesn’t snapshot anything. A lock date is a rule, not a record. It doesn’t store what the balance sheet was when you signed off, so it can’t tell you it’s different now.
• It doesn’t alert. If someone with rights posts into a locked period, Xero doesn’t email you or raise a flag. You only find out if you happen to look.
• It doesn’t ask why. There’s no forced reason or audit note attached to a change in a closed period - the why lives only in someone’s memory.

In short: a lock date is a gate, not a witness. It can slow the door - but it doesn’t watch it, doesn’t remember what was inside, and doesn’t tell you when someone with a key goes through.

What to add so you actually know

Keep your lock dates - but pair them with the three things they don’t provide:

• A snapshot at sign-off: a record of exactly what every balance was when you closed, so “has anything moved?” becomes a factual comparison, not a hunch.
• Automatic re-checking: something that compares that snapshot to live Xero on a schedule, so you learn about a change the next morning, not at year-end.
• Attribution and a reason: the document, the person and the date behind any change, plus a required note before it’s accepted.

Together, those turn “I hope nothing’s changed” into “I’d know if it had.” That’s exactly the gap Postlock fills on top of Xero - read-only, so it can never alter your ledger. See also what to do when a closed period changes.

Frequently asked questions

Do Xero lock dates stop all changes to a closed period?

No. They stop most users, but advisers/admins can post past the lock and can lift or move it. Lock dates deter accidents; they don’t guarantee a period is frozen, and they don’t tell you if something moves.

Why did a number change even though I set a lock date?

Most likely someone with adviser rights lifted or worked past the lock, or an integration posted a historic transaction. Xero doesn’t alert you when this happens, which is why the change is a surprise.

What’s the best way to protect signed-off numbers in Xero?

Keep lock dates and tight user roles, but add monitoring: snapshot the balances at sign-off and compare them to live Xero on a schedule, so any post-lock change is caught, attributed and explained.