One of the most common questions landlords ask is whether they would pay less tax by owning their rental properties through a limited company instead of personally.
It is an understandable question, but it is also one that is surprisingly difficult to answer properly without running the numbers.
The answer depends on far more than simply comparing Income Tax with Corporation Tax. Your existing income, mortgage interest, ownership structure, finance costs, the number of associated companies and whether profits are retained or extracted can each make a significant difference.
The Property118 Buy-to-Let Tax Comparison Calculator also considers salary optimisation, including the tapering of the Personal Allowance once adjusted income exceeds £100,000.
Why salary optimisation matters
Many company ownership comparisons assume that profits are either retained in the company or extracted entirely as dividends. In practice, that may not produce the most efficient result.
Where a landlord company has working directors, a commercially justifiable salary may reduce Corporation Tax and make better use of available Personal Allowances. The optimum figure will depend on existing income, National Insurance thresholds, employer National Insurance, payroll costs and whether the individual is already above the Personal Allowance taper threshold.
The £100,000 Personal Allowance trap
The Property118 calculator also takes account of the rule that reduces the Personal Allowance by £1 for every £2 of adjusted income above £100,000. By the time adjusted income reaches £125,140, the Personal Allowance is fully withdrawn.
This can be particularly important for landlords because rental profits, salary and dividends can all affect the overall income position. A structure that looks efficient at first glance may become less attractive once the lost Personal Allowance is properly factored in.
What the calculator considers
The calculator allows users to enter other UK taxable income, gross rent, mortgage interest, non-finance costs, ownership shares, associated companies, tax resident status, and company profit extraction preferences.
It then compares personal ownership with company ownership before and after salary optimisation. The results include Income Tax, Corporation Tax, employer and employee National Insurance, Section 24 finance cost relief, company retained profit and a simple ten-year straight-line comparison.
Why the result is still only a starting point
The calculator is intended to provide a useful screening tool, not a formal tax calculation or recommendation.
It does not deal with every possible issue, including SDLT, CGT, ATED, Employment Allowance, Scottish income tax, pension contributions, student loans, Gift Aid, Marriage Allowance, losses brought forward or detailed anti-avoidance considerations.
It also assumes that any salary paid by a company is commercially justifiable. That is important because salary should reflect real work carried out for the company and should not be treated as a purely mechanical tax-saving entry.
Use the calculator as the beginning of the conversation
If the calculator shows a significant difference between personal and company ownership, that does not automatically mean incorporation is the right answer.
Equally, even if the annual tax difference appears modest, incorporation may still make commercial sense for reasons such as succession planning, refinancing flexibility, liability management, business continuity, retirement planning and future portfolio growth.
Tax is only one part of the decision. The wider commercial objectives are often just as important.
