Expert services provided outside UK to UK tour operator -how is VAT recovered?

Our company engages experts to speak during our tours. Most of these experts provide these services on an ad-hoc basis (say up to 21 days a year) and do not charge VAT because they would be under the threshold. However occasionally we engage a professional who is registered for VAT. As that professional is supplying his services outside the UK, should they charge VAT or not? If they should, does it follow then, that under the TOMS scheme, a tour utilising a professional charging VAT will always be less profitable than one utilising an expert that doesn't, all other things being equal? Or is there a way in TOMS for the VAT to be recovered to even this out?

Hi,
Under the place of supply rules as the speaker is UK based and their supply is to your UK business VAT in the UK woulsd be charged.
Under TOMS you cannot recover input tax:
Introductions to TOMS
Thank you.