is there a way to retrieve a deleted invoice?
When you delete a transaction, invoice, receipts or almost anything else in Wave, it's deleted entirely.
We take privacy very seriously at WaveHQ. If you don't want records of something to be kept, we won't keep it. There are a few exceptions that relate to our paid services and the government regulations we have to follow, but as a rule, if something is deleted on Wave, we don't keep that data around either.
You'll have to recreate that invoice manually.
Happy to help out!