This help document goes over the QuickBooks 'Duplicate Document Number' error.
How it Works/What the Error Means:
QuickBooks Online automatically assigns estimate numbers to submitted Crik-IT orders (unless you're configured to have the QuickBooks estimate match the Crik-IT reference number).
If the transaction number QuickBooks is set to assign to an estimate already exists, QuickBooks will throw an error that looks like this:
"Message: BadRequest. Details: Duplicate Document Number Error : You must specify a different number. This number has already been used. DocNumber=1042 is assigned to TxnType=Estimate with TxnId=33537 , Validation Exception was thrown.Details:Duplicate Document Number Error : You must specify a differe[...]"
In the example above, the duplicate transaction is estimate 1042. In other works, this estimate already exists in QuickBooks, so QuickBooks cannot create a new estimate 1042. This also blocks all the subsequent estimates coming from submitted Crik-IT orders from being created.
How to Resolve the Issue:
Step 1: Turn on 'Custom Transaction Numbers' in QuickBooks
Do this by clicking the gear icon on the QuickBooks home page, click 'Accounts and settings' then click 'Sales'.
Edit the 'Sales from content' section and turn on the Custom Transaction Numbers. Make sure to click the Save button.
Step 2: Change the Offending Estimate Number
Do this by going to the offending estimate (in our example, estimate 1042) and click 'Edit'.
On the estimate, change the number in the 'Estimate no.' field to a number you are unlikely to ever use in the future, so you decrease the chance of the issue re-occurring. Make sure you click 'Save and close'.
Step 3: Turn off 'Custom Transaction Numbers' in QuickBooks
Do this by clicking the gear icon on the QuickBooks home page, click 'Accounts and settings' then click 'Sales'.
Edit the 'Sales from content' section and turn off the Custom Transaction Numbers. Make sure to click the Save button.
Once you've done the steps above, QuickBooks will be able to create and assign estimate numbers to submitted Crik-IT orders again; and any Crik-IT orders with this QuickBooks error will sync automatically.