Higher rate income tax for non resident landlord?

It's well known that non resident landlord who let UK property are subject to basic rate tax at source (currently 20%). They have a choice either to accept this or file to receive the rents gross and then account for income tax via the normal self assessment process. But, what if there UK income exceeds the basic rate band? Would they still be subject to 20% income tax or would they then be subject o the higher (40% or 45/50%) rate of income tax? ITTOIA 2005, s 269 ('Territorial scope of charge to tax') states that the 'profits of a UK property business are chargeable to tax under this chapter whether the business is carried on by a UK resident or a non-UK resident'. Therefore UK rental income could be taxed at 40% or above if the landlords income exceeded the higher rate band. There are special rules for UK dividends and bank interest which can limit any UK liability to the tax deducted at source (if any). However, these rules don't apply to UK rental income. Therefore if a non resident landlord had rental income of £50,000 they would be subject to 40% income tax on the rents in the higher rate band. This applies whether they are taxed at source or not. If they were taxed at source 20% would still be deducted but they'd need to account for the additional tax due at the end of the tax year.