Unique auto-increment number tied to User and Account

[TitasB]

I need an auto-incremented invoice number for quote, which would be separate for each user (in portal) and for each Account.

Hypothetical example:
User A creates a 4 invoices for Account X -> 4th invoice number is customPrefix+004
User A creates 2 invoices for Account Y -> 2nd last invoice number is customPrefix+002
User B creates 3 invoices for Account X -> 3rd invoice number is customPrefix+003 (with default invoiceNumber functionality it would be prefix+009)

Is such functionality possible and what approach for this issue would you recommend?

[tarasm]

I think, you can create hooks with needed logic, https://www.espocrm.com/documentatio...lopment/hooks/.