I have a problem I need to solve and have been trying to think of a way to use VBA to solve it. It doesn't have to be done in Excel if there's another way to do it, but I thought I'd start there.

We get lump sums paid by clients, and don't know which invoices they're paying. I'd like to find a way to go through all the permutations of their outstanding invoices to get the most likely invoices they're paying.

I've been trying to find a way to report back all possible sums given a list of, say, ten invoices. I know permutations soon reach huge numbers, but given that order wouldn't be an issue here I imagine there'd be some saving.

Does anyone have anywhere they could point me for help? I've been Googling this for a while now but am having trouble coming up with a decent search term. I'm sure this sort of thing must be well documented somewhere, if I just knew what I was searching for!

Thanks for any help you can offer
skt1974

Before viewing the algorithm to solve the problem, there is a need to address some possible conflict you can face.

If for instance you have three envoices of 1 euro (or dollar, pound, etc.)), 2 euro and 3 euro and ona payment of 3 euro, you don't have any chance to decide if the payment is related to the first two envoices or to the third. is my doubt clear enough?

Mario

Mario