Admin Beginner

Accounting period lock — close a month so nothing here can change it

5 min read Owner, Finance Updated September 2026

Section 01

Why lock a period

1 minute

Once your accountant has closed August — VAT filed, stock valued, the management accounts sent — a receipt booked on the 28th, a customer payment dated the 20th or a voided invoice quietly changes numbers that have already been reported. Brytebuild feeds those numbers to Xero and Sage (invoices, receipts, purchase bills, cost-of-sales journals), and every accounting system has a lock date for exactly this reason: Xero's period and adviser lock dates, Sage's year-end lockdown, QuickBooks' closing date, Odoo's lock dates, Business Central's allowed posting range and closed inventory periods. This is Brytebuild's.

Section 02

The two dates

2 minutes

Navigate toSettingsComplianceAccounting period lock
DateWho it bindsUse it for
Lock for everyone except company adminsEvery user except the company owner and roles with company settings access (the same people who may move the dates). Xero calls this the period lock date; Sage gives the same people an override permission.The last day of the most recently closed month. Move it forward each month-end. Admins can still post an accountant's adjustment into it.
Lock for everyone, admins includedEverybody, the owner too. Xero's adviser lock date.The last filed year-end. Nothing is posted on or before it by anyone.

Both are on or before dates. Either can be moved forwards or backwards by a company admin — there is deliberately no irreversible lock, because one wrong click would be permanent — and every change is written to the audit log with the old and new values and shown on the card as Last changed … by …. A company with neither date set behaves exactly as before.

Section 03

What is refused

2 minutes

Anything with a financial effect whose own date falls on or before the lock that applies to you:

ActionThe date that is checked
Every stock movement — goods receipt, consumption, works-order completion, waste, adjustment, stock take, transfer, despatch, returnThe movement's time. Movements are dated now, so this bites only on offline shop-floor actions replayed with a pressed time inside the locked month — the same rule Business Central applies to a closed inventory period: no value change of any kind.
Issuing an invoice or credit noteThe issue date, and the tax point where one was set — a tax point inside a closed month would move VAT into it. Refused before a number is allocated, so nothing is burned.
Recording a customer receipt; voiding oneThe payment's received date — the one AR entry you can backdate. Voiding reverses the receipt on its own date, so a receipt inside the lock cannot be voided either.
Goods-in with a supplier invoice dateThe supplier's invoice date — the purchase bill Sage receives is dated on it.
Keying an exchange rateThe rate's date — a rate keyed for a closed month would re-value that month's unvalued documents. The feed catching up never re-values a locked month either.
What you see

A refusal reads as a sentence, wherever it happens: “Your books are locked up to 31 Aug 2026. Receipt RCPT-2026-00002 dated 20 Aug 2026 cannot be posted. Post it dated after the lock, or ask a company admin to move the lock date under Settings → Compliance.” A refused payment stays as an editable draft, so you can change its date and record it again.

Section 04

Day to day

1 minute

At each month-end, once the accountant confirms the month is closed in Xero or Sage, move the first date to the last day of that month. When the year-end accounts are filed, move the second date to the year-end. If a genuine correction to a closed month is needed, the admin posts it (first lock) or moves the date back, posts, and moves it forward again — all of which is on the audit log. Keep the lock here in step with the one in your accounts: Xero and Sage refuse the same postings on their side, and a document that passes here but is refused there shows as a failed sync in Settings → Integrations.

Not covered

Per-user posting ranges (Business Central); an irreversible lock (Odoo's hard lock); a separate “exceptions to closing date” report beyond the audit log; automatic month-end locking; locking the Xero or Sage side from here.

What's next