Upvote:1
USD, EUR, and GBP are the most common currencies for exchanging in Iran, so firstly you will certainly be able to exchange your GBP note. Secondly, I recommend you to exchange your note from an authorized exchange shop rather than a bank as in Iran, exchange shops always have better rates than banks.
Upvote:3
GBP is amongst most popular foreign currencies in Iran and I believe you will be able to exchange it easily.
I have no experience with exchanging GBP myself, however, I had no problem in exchanging 100,200ies of Euro (in Rasht, a rather small city in the Northern Iran); 50 GBP (or even bigger notes) should be fine! [ but anyway you should get used to carrying too much paper, as eventually in Iran you will! ]