Originally Posted by
dpdapper
Alternatively, is there any reason I can't simply mail the stamped forms from the US on my return?
No reason at all not to do this. Perfectly fine.
[N.b. If you are posting in MUC, I would put german stamps on.]
However, some of the refund companies do also have reclaim desks at airports, which can process the transactions there and then (either for cash - with a further fee charge, or refund to cheque (posted) or back onto credit card).
You might be near one in MUC.
Or possibly even in US.
These aviod the postal risk completly