Within Method, all QuickBooks transactions apps (Estimates, Invoices, Sales Orders, Sales Receipts, etc.) have a checkbox called Wait for approval before syncing.
This is a checkbox to indicate whether or not the transaction has been synced to QuickBooks:
Checked - The transaction will NOT be synced to QuickBooks and will not exist in QuickBooks.
Unchecked - the transaction is synced and exists in QuickBooks.
When a transaction has been synced with QuickBooks, it can no longer be set to a state where it isn't synced. Thus, checking this box when it is already synced will do nothing.
Leads and Transactions
By default, transactions assigned to Leads will have the Wait for approval before syncing checkbox checked. If the checkbox is unchecked, then two things occur:
The transaction is synced to QuickBooks.
The lead immediately converts to a customer.
Transactions Lists and Needs Approval Filter
Transaction lists have a filter view that allows you to list all the transactions in the grid which required approval before syncing called Needs Approval. Using this filter, you can see which transactions are set to Waiting for approval before syncing.
Customizing for Sync Approval
To use the sync approval feature in your own customizations locate the table and field name. Note, this feature only works with tables that sync with QuickBooks.
QuickBooks Entities (Customer, Vendor, Employee, and OtherName) look for IsLeadStatusOnly.
QuickBooks Transactions look for IsWaitingForSyncApproval.
If these fields are set to True, then the record will not sync.