Period Lock
A period lock is a "locked through" date set on a book, enforced by the database, that refuses any posting on or before it and can only ever be moved forward, never backward.
In short
The mechanism behind closing the books. Set a lock through June 30th, and no categorization, manual entry, or reversal dated on or before that date can post — not even one that tries to bypass the application. The lock can move to July 31st later, but never back to June 15th.
Also called: locked period, locking a period
A period lock is one date recorded against a book, before which nothing may post. Not a status on individual entries, not a workflow state — a single boundary in time that every write is checked against.
It moves forward only. A lock can be extended to a later date and never rolled back to an earlier one, and that asymmetry is the entire mechanism rather than a missing feature. A boundary that could be moved backwards would provide no assurance at all, since anything it prevented could be permitted again by whoever wanted to.
Enforcement is in the database, which is what makes the guarantee worth stating. It holds against a categorization, a manual entry, a reversal and a later import equally, and it holds against the application itself rather than depending on the application to respect it.
It is the mechanism, not the routine. Month-end close is the sequence that ends in setting one, and the value of the lock depends entirely on that sequence having happened first.
What people get wrong
- Trying to move a lock backward to reopen a period — it's refused by design; the lock can only ever extend forward.
- Locking a period before reconciling it — that just means finding a problem later that can't be fixed in place anymore.
- Assuming a locked period blocks reports as well as postings — locking only stops new entries from posting; every report can still be pulled for a locked date range.
Common questions
- Can I unlock a period if I need to fix something in it?
- Not directly — a lock can only move forward, never backward. The fix is a reversing entry dated after the lock, not reopening the past.
- What happens if something tries to post before the lock date?
- It's rejected outright, with a clear reason pointing to the lock — nothing silently slips through into a closed period.
Machine-readable: /api/knowledge/concept:period-lock