Do we have a option to close the period on monthly basic ? for example if we are working on August month then I want to lock the July month for any posting.

Hello there, Murtaza1988.

I appreciate you for letting us know about your concern by posting it in the Community forum. Let me share a few details on how QuickBooks lock the previous transactions.

It would be great to lock transactions every month. However, QuickBooks doesn't have a specific field to lock our transactions per month. The Close the books option in the settings is mainly for fiscal year closing date. 

What we can do is to make sure we'll reconcile recorded transactions within QBO every month. Then, we can run the Reconciliation report and use it as a reference to check those transactions that should not be changed or touched. Here's how:

1. Go to Reports on the left panel.
2. In the search box, enter Reconciliation report.
3. Make sure to set the correct account and date because the system generates depend on the setup.
4. Locate the reconciled period. Then, click View under the Action column.

Note: We only use it as a reference to figure out which transactions have already cleared. Also, let me attach this article for more details about closing the book to lock past transactions: Learn how to close your books in QuickBooks Online. 

Please don't hesitate to post again if you have other questions or if there's something you need about QuickBooks. I'm just a post away. Take care and have a good one!