What would be the international code for sending a return fax from Spain to here?
The International code for UK is 44 and you miss off the 0 of the local code so from spain the code for Bournemouth (normally 01202) would be 00 44 1202 nnnnnn In most countries starting a call with 00 says it’s international. Note that you may have to precede with 9 or whatever the local equevalent is for and “outside line” in an office situation.