Period Close & Lock — the main screen
drop a screenshot at assets/screenshots/guides/period-close-lock.png to replace this
1. HOW IT WORKS
By default, nothing is locked — a business only gets a lock once an owner explicitly sets one. Setting a lock is simple: pick a date (say, June 30th), and from that moment on, any transaction anywhere in the system — a sale, a bill, an adjustment, a payroll run, a manual journal entry — that's dated June 30th or earlier is rejected outright the instant someone tries to save it. Not hidden, not warned-and- allowed — rejected.
Period status
Crucially, this check happens as the very first thing the system does when trying to record any financial entry, before anything else is even validated — so a closed-period rejection can never be accidentally skipped by some other part of the process. It doesn't matter which screen someone is using; the same protection applies everywhere, automatically.
2. WHY TODAY IS ALWAYS LEFT OPEN
You can never set a lock date that covers today or the future — only the past. This is deliberate: if you discover a mistake in a prior, closed period, the correct fix is a reversal entry dated today (see the Chart of Accounts & General Ledger guide) — never a change to the original closed date. If today itself could be locked, you'd be unable to make that correcting entry at all. A real period-close protects history; it never traps you out of fixing it going forward.
3. WHAT LOCKING DOESN'T DO
The lock is go-forward only from the moment it's set — it doesn't retroactively validate or touch anything that already exists in that period. It simply stops anything NEW from landing in that window from here on. This means setting a lock is always a safe, additive action — it can never itself change or damage historical data.
4. HOW IT CONNECTS TO THE REST OF THE SYSTEM
- Every module — Sales, Purchasing, Inventory, Production, Payroll, manual Journals — routes every financial write through the same central posting engine, and this lock check runs there, once, for everyone. There's no module-by-module gap where the lock might not apply.
- Reversals — same-day reversal entries for correcting a prior, closed period always remain possible, specifically because today is never lockable.
5. WHY IT SCALES FROM SMB TO ENTERPRISE
Small business
Lock last month once you've reconciled it, and stop worrying about an old transaction accidentally getting edited.
Growing business
A lock applies uniformly across every module — nobody on a bigger team can find a back-door screen that skips it.
Enterprise
Universal, first-checked, no-exceptions period-close enforcement is exactly the internal control auditors test for — built in by default rather than relying on staff discipline alone.
Quick Reference
Set/change the lock date ................. Settings > Accounting > Period Lock