The income generated from land or property in the UK is treated as arising from a UK property business. The underlying legislation defines this broadly to include all activities that produce rental income or similar receipts from UK land, whether the taxpayer is subject to Income Tax or Corporation Tax.

Although property income is treated as coming from a business, landlords are not generally regarded as trading unless they meet the normal trading tests. As a result, most trading-related tax reliefs, such as certain Capital Gains Tax reliefs, do not usually apply. Property business profits are instead calculated using principles similar to those for trading profits.

Since the 2017–18 tax year, the cash basis is the default method for calculating profits and losses for most individual landlords. However, companies and some other landlords must still use Generally Accepted Accounting Practice (GAAP).

A wide range of persons can carry on a UK property business, including individuals, partnerships, trustees, companies and non-residents with UK property income. Using an agent does not change who is treated as carrying on the business.

In most cases, all UK property income is treated as part of one single property business, allowing income and expenses across different properties to be combined. UK and overseas property, however, are treated as separate businesses. Activities carried out in different legal capacities, such as personally, as a partner or as a trustee, are also treated as separate property businesses for tax purposes.