From 2017-18, the cash basis is the default method of reporting profits or losses of a property business for most individuals with cash receipts for the tax year of £150,000 or less.
The profit or loss to be reported under the cash basis is found by calculating:
The total amount of receipts that the business received during the tax year, less the total amount of expenses that the business paid during the tax year.
In simple terms you only need to show money when it comes in or goes out. There is no need to account for debtors or creditors.
If you believe it is more appropriate to use traditional accounting, e.g. when the income is earned and when the expenses are incurred, you must make an election on your tax return.
For more information, please see
PIM1090 - Cash basis for landlords