Once an approved budget has passed the budget end date and is ready to be reconciled, it can be locked.  Locking the budget sets a date and time stamp which determines which invoices are included in the budget and which ones should be included in the next budget.  Any invoices entered after the budget is locked won't be included in the budget.

To lock a budget, click the Lock button:

A confirmation message will be shown: 

Once confirmed, the reconciliation process can begin.

If the budget needs to be un-locked, just click the Unlock button.

Next: Reconciling a Budget