{"id":"concept:period-lock","kind":"concept","label":"Period Lock","synonyms":["locked period","locking a period"],"definition":"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.","summary":"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.","explanation":["A period lock is a single \"locked through\" date recorded on a book. Once set, no entry — no categorization, no manual journal entry, no reversal — can post on or before that date. This is enforced by the database itself, not merely by the application's interface, so it holds even against a write that tries to bypass the app entirely.","The lock moves in one direction only: forward. It's possible to extend a lock from May 31st to June 30th later, but never to move it back to May 15th — a closed period is meant to stay closed, permanently, not get reopened because it would be convenient for one transaction. A lock that could be casually reversed wouldn't actually protect anything.","Locking pairs naturally with reconciliation: reconcile first, confirm the ledger matches the statement, then lock through that date. Locking before reconciling just means discovering a discrepancy later that can no longer be fixed in place, since anything dated in the now-locked range is refused.","Like every other tool that writes to the ledger, setting a lock previews first — showing the current lock, if any, and what it would become — and only actually applies once confirmed. Trying to post anything dated on or before an existing lock is rejected outright, with a clear reason pointing to the lock date, rather than silently allowed through."],"commonMistakes":["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."],"category":"close","questions":[{"question":"Can I unlock a period if I need to fix something in it?","answer":"Not directly — a lock can only move forward, never backward. The fix is a reversing entry dated after the lock, not reopening the past."},{"question":"What happens if something tries to post before the lock date?","answer":"It's rejected outright, with a clear reason pointing to the lock — nothing silently slips through into a closed period."}],"url":"/glossary/period-lock","relatedTo":[{"id":"concept:closing-the-books","relationship":"related","weight":0.9,"api":"/api/knowledge/concept%3Aclosing-the-books"},{"id":"concept:reconciliation","relationship":"related","weight":0.9,"api":"/api/knowledge/concept%3Areconciliation"},{"id":"concept:journal-entry","relationship":"related","weight":0.9,"api":"/api/knowledge/concept%3Ajournal-entry"},{"id":"concept:reversing-entry","relationship":"related","weight":0.9,"api":"/api/knowledge/concept%3Areversing-entry"},{"id":"tool:lock_period","relationship":"references","weight":0.7,"api":"/api/knowledge/tool%3Alock_period"}],"referencedBy":[{"id":"concept:posting","label":"Posting","url":"/glossary/posting"},{"id":"concept:fiscal-period","label":"Fiscal Period","url":"/glossary/fiscal-period"},{"id":"concept:reversing-entry","label":"Reversing Entry","url":"/glossary/reversing-entry"},{"id":"concept:closing-the-books","label":"Closing the Books","url":"/glossary/closing-the-books"},{"id":"concept:month-end-close","label":"Month-End Close","url":"/glossary/month-end-close"},{"id":"concept:year-end-close","label":"Year-End Close","url":"/glossary/year-end-close"}],"license":"https://creativecommons.org/licenses/by/4.0/","attribution":"BalanceMCP — https://balancemcp.com"}