I have a question about the two Cumulus vouchers (yellow), e.g. 5x points and 500 points, can you hand them in at the same time? It doesn't say "cannot be cumulated" anywhere.

Some branches were kind enough to try scanning them in, but unfortunately I can't remember whether it worked or not. Some branches unkindly said: "it doesn't work with 2!!!" Without trying it out.

So... Can you hand them in at the same time?
Many thanks