Finance Act
The Finance Act 1995 allows overseas landlords or companies whose registered office is overseas (including the Channel Islands and the Isle of Man) to apply for tax self-assessment, and, if appropriate, an approval certificate can be issued.
However, where no certificate is available, the agent collecting the rent has a statutory obligation to implement a tax deduction (at the relevant percentage for the period) before remitting the rent and then paying the tax to HMRC.
There is also a statutory obligation upon agents to notify HM Revenue and Customs of all rents collected and deductions made on behalf of every UK-based landlord (over and above the obligations in respect of non-resident landlords) during the preceding year, and there are a couple of pieces of legislation under which they may request such a list.