Hello everyone,

I'd like to ask about what's needed in a partial refund. Let me tell you what happened. The numbers are examples:

1- We sold marketing service for $1,000
2- We issued an invoice of $1,000 and got paid
3- After few months, at the end of the deadline, we couldn't deliver all of the marketing
4- The company that bought marketing from us wants $200 back.
5- We'll wire $200 back, but want to make sure we're doing it right

Do we need a refund invoice from them? If yes, where can I find info about what should be in that invoice?
What else do we need from them for proper book keeping, other than their bank info?

Thanks a lot in advance!

You need no invoice, assuming you have a paper or email trail asking for some refund.
Bank routing number.

Normal practice would be to issue a credit note