Complex income: bonus, commission, overtime

Complex income means earnings beyond a basic salary: bonus, commission, overtime, shift allowances or a second income. UK lenders treat these very differently, using anywhere from 0% to 100% of a given element. The figure a lender uses, not the figure on your payslip, sets your maximum loan. The same applicant can be offered far more by a lender that counts a higher share of their variable pay.

The percentage problem

A payslip showing a large bonus does not mean a lender uses all of it. One lender might count 100% of a regular, evidenced bonus; another 50%; another none. Overtime, commission and allowances are treated the same patchy way. So affordability is not really about what you earn: it is about which lender's rules use the most of what you earn. That is the single biggest lever on a complex-income case.

How much typically counts

Income type	How lenders often treat it
Regular bonus	From 0% up to 100%, frequently averaged over one to two years
Commission	Often 50% to 100% if regular and evidenced
Overtime / shift allowance	Commonly 50% to 100%, depending on regularity
Second income	Counted in full by some lenders, partly or not at all by others

Indicative ranges only. Every lender sets its own percentages and evidence rules.

What to have ready

Payslips covering enough months to show your variable income is regular.
Your latest P60, and ideally the previous one, to evidence annual totals.
For commission, a clear pattern over time rather than a single spike.
Details of any second income, with its own evidence.

Proposed rule changes, not yet in force

What the FCA has proposed (CP26/18)

On 9 June 2026 the Financial Conduct Authority published consultation paper CP26/18, "Mortgage rule review: supporting first-time buyers and underserved consumers". The consultation closed on 28 July 2026. The FCA says it will publish a policy statement once it has reviewed responses, and expects to do so in the second half of 2026. As at 29 September 2026 no final rules had been published, so nothing has changed yet: the current rules still apply.

Variable and irregular income: making clear that lenders can agree payment schedules other than monthly (for example quarterly), changing references to "monthly payments" in its rules to "regular contractual payments", and adding guidance with examples of evidence for assessing affordability where income varies.
Past credit problems: making clear that its "credit-impaired customer" definition (which includes arrears of three months or more in the last two years, a CCJ over £500 in the last three years, or a bankruptcy order or IVA in the last three years) is meant only for debt consolidation mortgages and reporting, and should not be treated by lenders as a factual indicator that a mortgage is unaffordable.
Interest-only: removing the need for a credible repayment strategy where the interest-only part is less than 25% of the lender's valuation, and adding converting to repayment and a follow-on product as examples of a credible repayment strategy.

The FCA says its proposals keep responsible lending requirements in place and do not remove lenders' duty to check that a mortgage is affordable. Lenders remain free to set their own credit risk appetite.

Source: FCA, CP26/18: Mortgage rule review, supporting first-time buyers and underserved consumers.

Common questions

How much of my bonus or commission counts?

It varies widely. Some lenders use 100% of a regular bonus or commission, others use 50%, and some ignore it entirely. The same applies to overtime. Because the percentage differs so much, two lenders can offer very different maximum loans on identical payslips.

How do lenders evidence variable income?

Usually from payslips and your P60, often averaging the last one or two years, or sometimes taking the lower of the latest year and the average. A consistent, growing bonus is treated more generously than a one-off.

What about a second job or side income?

Many lenders will consider a second employed income or self-employed side income, but only some combine it fully with your main income. This is a common reason a perfectly affordable application is declined: the lender simply does not count part of what you earn.

I earn plenty but keep being offered too little. Why?

Almost always because your lender discounts your variable income. A lender that uses a higher percentage of your bonus, commission or overtime can lift your maximum loan substantially without you earning a penny more.

Adam Parker

Founder, MortgageExplained

Adam spent over eight years as a mortgage adviser at Just Mortgages, with further experience in commercial finance. He is CeMAP and CF qualified. He built MortgageExplained to do one thing well: explain mortgages in plain English, so you know where you stand before you speak to a regulated broker. Every page on the site is written by Adam.

Last reviewed: 30 June 2026