If you rent out property you will pay income tax on the difference between the rents you have charged in a tax year, less any allowable expenses and charges.
If you don't already receive a tax return, you must notify HMRC of any rental income by 5 October after the end of the tax year (5 April). You will usually need to fill in a tax return if you get money from renting out property. Unless you receive a tax return, 5 October is also the deadline for notifying your tax office if you have sold a property and made a taxable capital gain. The deadline for making a paper tax return is 31 October. For an online return the deadline is 31 January.
You should inform HMRC of your property income no matter whether you are making a profit or a loss from the property. But you pay tax only on your net rental profits – that is, your rental income, less the allowable expenses (deductions) of letting. So if you have no profit, you will have no tax to pay.
You can deduct certain expenses from the total rental income. The tax you pay is based on the rental income figure after deduction of expenses. If you choose to let out your UK home while you live abroad, you are liable to pay tax on any profit you make from renting out a property.