Academy

Lock a closed period

Set an accounting lock date so nobody can post, change or remove an entry in a month you have already closed.

Accounting 6 steps 2:12 video Administrator
Where to find it SettingsAccountingFiscal Year & Opening Balances

Before you start

Lock a period only when its figures are final: the statements are sent, the VAT is filed and the reports are checked. The lock applies to everybody in the company, administrators included, so post anything you still need in that period first.

Steps

  1. Open Settings and click the Accounting tab. Scroll down to Fiscal Year & Opening Balances.
  2. In Accounting Lock Date, choose the last day of the period you have closed - for example 30/09/2026 when September is done.
  3. Click Save Settings at the top of the page. From now on nothing dated on or before that day can be posted, reset or removed.
  4. To see it work, open Accounting > Accounting > Journal Entries, click New and give the entry a date inside the closed period, for example 15/09/2026. Fill in two balanced lines.
  5. Click Post Entry. SiaOne refuses and shows a red message: "The period up to 2026-09-30 is locked; an entry dated 2026-09-15 cannot be posted or removed there." Change the date to a day after the lock and the entry posts as usual.
  6. To open the period again, go back to Settings > Accounting, clear Accounting Lock Date and click Save Settings.

Tip

The lock covers invoices, bills, payments, cash purchases, refunds and journal entries. Each month, change the date to the last day of the month you have just closed.

Note

Tax Lock Date sits next to it. Use Accounting Lock Date to block postings; the tax lock date is saved but does not block anything yet.

Important

Need to correct a closed month? Do not reopen the whole period if one entry is wrong. Post a correcting entry dated after the lock instead - see Record a manual journal entry.

What happens next

Closing a period is the last step of the month-end routine. To record the entries that belong to the next period, carry on with Record a manual journal entry or any other document - they all use today's date.

Was this lesson helpful?

Keep learning

Register a fixed asset and run depreciation Add an asset such as a vehicle, see its depreciation board, confirm it, and post the depreciation each month. Accounting7 steps2:18 video Reconcile a bank statement Import the statement from your bank, let SiaOne match each line to a payment, and post the bank charges your books do not have yet. Accounting6 steps Record a manual journal entry Post your own debit and credit lines for something no invoice, bill or payment covers - such as a bank charge with VAT, or a correction. Accounting5 steps1:47 video