Dont know about Borovets but my mates had trouble using the ATMs in pamps. Think it was to do with the new chip n pin. I go out in Feb but gonna take sterling
i think the only one that works is the one in the flora hotel.we were in borovets at xmas and the atm outside the rila would not accept credit cards??????
just make sure you take sterling as a back up as i don't think they charge any commission and you get a good exchange rate too