Some members require specific information to be added to their invoices, such as the registration number of their trainer. Often this is because of requirements set out by the health insurance provider.
Add Extra Invoice Information for a Member
Go the member's profile
Select the Overview tab at the top (if it's not already selected)
Under Personal Info, find the field titled 'Extra invoice info'.
Enter in any custom information that is needed
Select Save
Any information you add here will appear on all of the member's invoices.