The Key to finding out why your invoice isn’t syncing is to check the Event Log.
Checking the Event Log:
Go to Reports > Business Reports > Log Reports > Event Report
This will show you a log of all the errors for your invoices. This would be the FIRST thing I would do if your invoices are not showing up. In the case of this article, you will find the following error:
Click on image to enlarge
The key parts you need to be looking for are the following:
1) The invoice number in the top right hand corner: In the example above the invoice number is 641. This defines which invoice the error is talking about. If you are looking for a specific invoice, you will find it her.
2) The error message: This error message will let you know what the issue is.
3) The Reason For the Error: The highlighted areas in the screenshot above are where you will find this specific information. For guides on the specific errors, please go to the articles below:
Invoice not of valid status for creation
Signature_invalid:Failed to validate signature or Unknown response code: 500 or Call to authorize a partner xero application failed
Account ‘XXXX’ has been archived, or has been deleted
TaxType code does not exist or cannot be used for this type of transaction
Payment amount exceeds the amount outstanding on this document
Associated parent record is not uploaded to Xero, sync to upload
Xero integration will not work until valid accounts are entered
The specified contact details matched an archived contact. Archived contacts cannot currently be edited via the API
Invalid status for modification
If there is no article for the error, please email email@example.com