Close a period (lock your books)
Lock finished months so posted records can't be changed, and reopen only with a reason.
Once a period is closed, invoices, bills, journal entries, credit and debit notes, revenue and payments dated on or before the lock date can no longer be created, edited or deleted. They can only be voided or corrected in the current open period. This is what an examiner checks when they ask whether posted books can still be changed.
Where: Administration › Period Closing.
Close a month
- Make sure the month is complete: invoices issued, bills and expenses entered, payments recorded and the bank reconciled.
- Under Close the books, set Lock through date (for example the last day of the month).
- Add a Note, such as August 2026 closed.
- Click Close Period.
Reopen for a correction
Under Reopen (correction), enter a new lock date (or leave it blank to reopen everything) and a Reason, which is required. Then click Reopen Period.
Every close and reopen is kept in Close / Reopen History.
Tip: A good habit is to close each month around the 10th of the next month, after your accountant has reviewed it.