If you are paid under the Construction Industry Scheme and a bank has treated you like a risky applicant on uneven income, you are not imagining it. The real issue is usually not what you earn, but how CIS income counts in the eyes of the lender. Get that assessment wrong and your borrowing can be cut sharply. Get it right and the numbers often look far stronger.
For many CIS workers, that is the difference between settling for a smaller mortgage and buying the property they actually want. Mainstream lenders often default to rigid checks that do not reflect the way subcontractors are paid. Specialist underwriting takes a more realistic view and, in many cases, that leads to a higher loan amount and a smoother application.
How CIS income counts with mortgage lenders
CIS income is usually assessed using your gross income from payslips and CIS statements, rather than the lower figure that may show on tax calculations after allowable expenses. That distinction matters. If a lender only looks at net profit or taxable income, it can understate your true earning power.
This is where lender policy makes a big difference. Some lenders treat CIS workers in a similar way to employed applicants, using an average of recent gross income evidenced by CIS payslips or remittance slips. Others insist on SA302s and tax year overviews and base affordability on declared profits instead. Neither approach is universally right or wrong, but one may be far more favourable depending on how you work and how your income has been trending.
In practice, the most helpful lenders often look at your most recent 3 to 12 months of CIS income and build affordability from there. That can work particularly well if your income is stable, your contract history is consistent, and you have not had long gaps between jobs. If your earnings have increased recently, using current gross income can produce a stronger outcome than relying on older tax figures.
Why high street lenders often get CIS wrong
The frustration for CIS applicants is that they can earn well, have solid deposit funds, and still be offered less than they expected. That usually happens because the lender is trying to fit a subcontractor into a standard employed or self-employed box.
If they class you as self-employed and use only end-of-year accounts or taxable income, they may miss the fact that CIS deductions are payments on account towards tax, not a sign of low or unstable earnings. If they class you as employed but do not understand the paperwork, they may ask for documents that do not properly evidence your income or delay the case while they work out what they are looking at.
That confusion can cost time as well as borrowing power. In a live purchase, delays matter. A lender that understands CIS from the start is far less likely to bounce the case back for avoidable queries.
What lenders usually look at
Although criteria vary, most lenders want a clear picture of consistency, sustainability and the likelihood that your income will continue. They are not only asking how much you earned last month. They want to see whether that level of income is believable and ongoing.
For CIS applications, that often means recent payslips or remittance slips, bank statements showing income credits, proof of ID and address, and sometimes SA302s with tax year overviews. If you have changed contractors or agencies, an underwriter may want to understand whether there were gaps and why. Short breaks are not always a problem, especially in construction, but unexplained gaps can trigger questions.
Credit profile still matters too. Strong CIS income can improve affordability, but it does not override missed payments, high unsecured debt or adverse credit. A good broker will look at the full case, not just the income side.
How much history do you need?
This depends on the lender. Some will consider applicants with as little as three months under CIS if the wider profile is strong and there is previous experience in the same line of work. Others prefer six or twelve months. If you have worked in construction for years but only recently moved into a CIS arrangement, there may still be options.
The key point is that short history does not automatically mean no. It means lender choice becomes more important.
Gross income versus taxable income
This is often the make-or-break detail. A lender using gross CIS income may assess affordability on what you are actually bringing in before tax. A lender using taxable income after expenses may arrive at a much lower figure.
Neither method is inherently generous or harsh. It depends on your accounts, expenses and payment structure. But if your goal is to maximise borrowing without changing how you operate, you need a lender that uses the income basis most favourable to your circumstances.
How to present CIS income properly
Strong cases are rarely just about strong earnings. They are about presenting those earnings clearly and in the right format for the lender. This is where many applicants lose momentum by applying direct.
The cleaner the packaging, the easier it is for an underwriter to say yes. That means matching payslips to bank credits, explaining any fluctuations before they are queried, and showing continuity of work where possible. If there is a good reason for a dip in income, such as weather disruption, illness or a planned break, it is better to frame it early than leave the lender to assume the worst.
It also helps to avoid unnecessary contradictions. If your bank statements show regular income but your declared figures vary because of legitimate tax planning, the application needs to explain that properly. Otherwise the lender may simply default to the lower number.
How CIS income counts if you want to borrow more
If borrowing power is your priority, lender selection matters as much as your income level. Two lenders can look at the same CIS applicant and produce very different maximum loans.
One may cap income on a cautious annual average. Another may use a more current figure if your earnings are rising. One may be uncomfortable with a recent gap in work. Another may accept it as normal for the sector. This is why CIS mortgages are not really about finding a lender that says yes. They are about finding the lender that understands your income well enough to lend the right amount.
That difference becomes even more important if you are buying in an area where property values move quickly, or if you need to remortgage without being pushed into a lower loan because of a narrow affordability model.
Common issues that can affect your application
Irregular income is not always a problem, but unexplained volatility can be. Large swings month to month may lead a lender to average income over a longer period or discount the highest recent figures. If your work is seasonal, that needs context.
Recent self-employment can also be a sticking point. Some lenders want to see an established pattern under CIS, while others are more flexible if you have remained in the same trade. Likewise, if you have changed from PAYE to CIS, the transition should be explained clearly.
Deposit source matters as well. Gifted deposits, retained savings and funds from a property sale are all common enough, but each brings its own documentation. If the lender is already doing extra work to understand your income, you do not want avoidable questions on the deposit side too.
Why specialist advice makes a difference
For CIS workers, the challenge is rarely that there are no lenders available. It is that too many lenders assess the case in the wrong way. That is where specialist advice adds value quickly.
A broker who regularly places CIS cases can often identify early which lenders will use gross income, what history they need, how they view gaps in work, and which underwriters are comfortable with subcontractor income. That avoids wasted applications and helps protect your credit file from unnecessary searches.
It can also speed things up. When a case is packaged properly from day one, the lender spends less time asking basic questions and more time underwriting the mortgage. For buyers working to estate agent deadlines or remortgaging before a rate expires, that matters.
The Residential Mortgage Hub focuses on applicants whose income does not fit the standard mould, including CIS workers, fixed-term contractors and limited company directors. That specialist approach is often what turns a frustrating case into an approved one.
If you are wondering how CIS income counts for your mortgage, the answer is not just a formula. It depends on the lender, the paperwork, the history behind your income and how well the case is presented. The good news is that being paid under CIS does not mean you have to accept lower borrowing or a harder process. With the right lender and a clear application, your income can be assessed on its real strength.
