Notice that it doesn't matter if you are using Dedicated Sequential Numering for Credit Notes or a custom Incrementation. Billing Extension automatically detects your settings and apply changes accordingly. Moreover you can still use different Number Format if you like to.
Billing Extension version 2.2.8 or newer must be installed on each of your WHMCS. The following settings for Invoices must be the same:
- Next ID
- Dedicated Sequential Numbering
- Next ID
Billing Extension. In order to secure the connection across all your WHMCS, you need to generate a token using the provided feature.
Press the orange button to generate the alphanumeric token from one of your systems then copy it on the others and save. Make sure that all your WHMCS are set to use the same token.
In the provided textarea insert the SystemURL of all your WHMCS (one per line). To avoid any misunderstanding, visit Setup > General and note down the WHMCS System URL for every WHMCS you need to add. If for some reason the URL changes, don't forget to apply changes also on Invoice Sync. Keep in mind that Billing Extension notifies you about any possible problem in the Warning System.