Are you planning to leave the UK (whether on a temporary or permanent basis) and rent the property you have there?
In this case, you need to be aware of the NRL (Non Resident Landlord) scheme. Unless you have successfully applied to HM Revenue & Customs to receive the rental income gross, the lettings agent (or the tenant of the property if the rent is more than £100 per week) is required to deduct tax from the rental income, at the basic tax rate, which is currently 20%, and pay it to HMRC.
You will generally be required to file a UK self assessment every year as you will remain liable to UK tax.
Word of caution: you will have to apply to HMRC to be entitled to your UK personal allowance (if you have one), it is not allocated automatically.