Hi Ian,
Both are the same but the name varies depending on where you are located. In the US, it is often referred to as tax ID, resellers ID, sales tax ID while in the UK and most of the Asian countries it is referred as VAT ID. In Australia and New Zealand, it is called an ABN or GST registration.
So yes, if the supplier requires you to present your tax ID you can provide them your VAT ID details instead.
Hope this helps :)