Tax relief on charitable donations abroad?

Hi, I am wondering if anyone can help.  I have a client who wants her company to donate to a charity abroad.  It is a registered charity abroad, which she got involved with and is passionate about the work they do.  I am not sure if the same tax relief rules apply for donations abroad.  Called HMRC and they do not seem to be able to give me a decent answer or point me to any document or guide.

I would be very grateful if anyone has knowledge on this area.