VAT code for purchases from outside the EU

I've bought some software (not physical, purely licences for downloads) from the US. The invoice gives a European Union VAT number (beginning EU...) and then a bit further down states "Exempt Number: GBnnnnn" (where nnnn is my VAT number). It's the combination of numbers and terms that are confusing me. Do I use T24 to record as I do for similar purchases from within the EU? Or should it be another code entirely?