This is a really important one for us! When invoices are created it would be extremely beneficial if there is the option to merge several transactions/appointments to appear on a single invoice. Our clinics frequently invoice monthly in arrears e.g. to insurance providers, NHS or self-pay customers. There have usually been weekly appointments so there usually will be four appointments in one month. Whilst you can set up a custom email for all four invoices to appear, it is fiddly and it is still separate invoices which is unmanageable for payers.
We need an option whereby when you come to create an invoice, you can tick several transactions to be included in one invoice. This was available in our old software - practicepal.
Thank you in advance 
Hi Katie.
Thank you very much for your suggestion.
I am happy to inform you that it is in our roadmap to make it possible multi-appointment-to-one-invoice association, initially via Point of Sale, in a way that you can select the appointment each invoice item/entry of type service should be associated to. 
Kind regards,
Viktor