Within Teamwork, you may receive an error when exporting invoices from your site to QuickBooks Online.
The root cause of this message is that in QuickBooks Online, your company setup is set to use Custom transaction numbers.
When set to this mode, you are not permitted to use duplicate id/numbers for invoices you send over to QuickBooks Online.
The resolution to this issue is either:
- Login to QuickBooks Online and uncheck that setting and Save. You should then be able to successfully export from Teamwork.
- Alternatively, you can amend the Invoice Number/ID in Teamwork to avoid the clash.
- While viewing the relevant invoice in the Billing area of your project, click the edit pencil above the Invoice No./ID field.
For more information, see: Exporting an Invoice to QuickBooks Online