Feature Request: Record money received and calculate change

[dnk8n]

I am happy to explore implementing this. Just creating an issue to track. For now, the subject says enough. Will flesh this out as progress happens.

[dnk8n]

P.S. Would want this information on the invoice too

[Epse]

This shouldn't be too difficult, I presume

[Epse]

See commit above, this is a long ways from completing your request, but it's a start.