Two regimes, never both
In England & NI, a company buying a home for more than £500,000 pays a flat 17% on the whole price unless a relief applies. With a relief, it pays the higher rates for additional homes instead. Companies always pay the higher rates on cheaper homes. The 2% non-resident surcharge can be added to either. Scotland and Wales have no 17% rate.
Not covered here
Buying several homes, partnerships, trusts, transfers into a company you control (market value rules) and mixed portfolios. See the company purchases guide.