Mortgage affordability rules have not changed as dramatically in the last couple of years as some headlines suggest. The Financial Conduct Authority’s interest rate stress test has been part of UK lending since 2014, and the Consumer Duty came into force back in July 2023 — neither is new for 2026. What has changed is how much flexibility lenders now have in applying that stress test, and the FCA is currently consulting on further reforms aimed at self-employed, foreign-income and credit-impaired borrowers.
None of this means affordability has become a straightforward tick-box exercise. If you have bonus income, foreign currency earnings or a fluctuating salary, a broker who understands where each lender’s flexibility actually sits can still make the difference between an approval and a decline.
How the FCA’s Affordability Stress Test Actually Works
Lenders are required to check whether your mortgage would still be affordable if interest rates rose — commonly modelled as a rise of around 3 percentage points above the rate you are being offered, though the exact margin is at each lender’s discretion. This is not a new 2026 rule; it has applied in some form since the Mortgage Market Review. What has genuinely moved is the FCA’s position on how strictly it needs to be applied: its December 2025 review concluded that, with interest rates lower than they were a couple of years ago, a rigid stress margin can end up unnecessarily restricting access to mortgages that are otherwise affordable, and gave lenders more scope to reflect that.
Mortgage brokers can help you pass these tests by reorganising your finances, and they know which lenders apply the stress test more leniently or take product transfers into account. Some lenders also offer exclusions for specialists in particular sectors or high-income earners. You can read more about how lenders actually calculate affordability beyond a simple income multiple.
Brokers do more than hand the lender your figures — they help the underwriter understand your full financial situation. When you are facing a constrained lending market, that human context can make a genuine difference.
A good broker also helps you raise your debt-to-income ratio or lower your current obligations. To improve affordability, they may suggest consolidating loans or increasing your deposit. Lenders look closely at monthly spending patterns too, and a broker can help you adjust your outgoings before you apply. In the current lending climate, this all-round view of your finances is what makes the difference.
What the Consumer Duty Means for You as a Borrower
The FCA’s Consumer Duty has required lenders to prioritise good customer outcomes since it came into force in July 2023, and by now it is embedded in how lenders assess and advise on mortgage applications rather than a recent change. In practice, it means lenders check that a mortgage genuinely fits your circumstances, not just that you can technically afford the monthly payment.
A mortgage broker makes sure your paperwork meets these standards for a smooth mortgage application process. They know how to present your circumstances in a way that matches what lenders expect, which reduces delays and improves your chances of approval.
Because brokers already understand these requirements, working with one puts you at an advantage. A good broker helps you avoid the delays that come from poor-quality, missing or ambiguous information, and explains the small print in your mortgage offer before you commit to a deal.
How Lenders Treat Bonus Income
If you rely on bonus income, most mainstream lenders will only count a fraction of it towards your affordability calculation, and some ask for two years of bonus history before they will consider it at all. A broker can help you present your bonus correctly, evidencing a consistent trend and solid employer backing.
Some lenders take a more favourable view of bonus and commission income than others, and a broker who regularly places complex income mortgage applications will know which ones to approach. They will help you clarify whether your bonus is guaranteed or variable and how it is structured, which can make a real difference even under stricter criteria. In some cases a broker may suggest delaying an application until further bonus history is available, or highlighting other income streams to increase your borrowing capacity. The FCA’s current mortgage rule review (CP26/18) is also looking specifically at how lenders assess variable and irregular income, including bonus and commission-based earnings, so this is an area worth watching over the rest of 2026.
Mortgages for Foreign Currency Salaries
Earning in a currency such as US dollars or euros can be treated as a risk by some lenders, and many now apply more stringent affordability criteria to foreign-currency applicants than they used to. Some lenders decline foreign-income applications altogether. A mortgage broker can approach lenders who specialise in helping expatriate buyers on your behalf, and make sure your application highlights any consistent income streams.
A broker can also help you emphasise long-term contracts or UK-based assets when applying for lender approval, and make sure underwriters properly understand your situation as an expat applicant. They keep track of changing regulation around foreign income too, which is particularly useful if you are a foreign national or a returning UK resident with a varied income profile. Foreign currency mortgages are one of the areas the FCA’s CP26/18 consultation is looking to improve access to, so lender appetite here may shift further over the coming months.
Applying Buy-to-Let Affordability to Short-Let Income
If you are planning to let a property on a short-term basis, expect closer scrutiny. Lenders commonly ask for evidence of consistent rental income, and some will let you factor in a higher rent figure once you can demonstrate it. A broker can help you put together robust rental projections to bring lenders on board, and works with lenders who accept holiday-let or Airbnb-style rental income on a buy-to-let mortgage, which widens your options as an investor.
Many lenders still prefer to underwrite long-term rental strategies, and a broker helps bridge that gap by presenting seasonal variation, realistic income projections and comparable evidence. Accurate figures make a short-let proposal more credible and more likely to be accepted. Some brokers will even work with your property manager or letting agent to confirm your income model and strengthen your case as an investor.
Why Online Mortgage Calculators Do Not Tell the Whole Story
Online mortgage calculators are a useful starting point, but they rarely reflect lender-specific stress testing, and most will not account for bonus pay or foreign income properly. A broker can run a tailored affordability assessment using your full financial profile with a tool such as our mortgage affordability calculator, giving you a clearer and more accurate picture of what you could borrow.
A broker’s tools can also apply fluctuating rates and current lending criteria, and factor in your future plans — moving house, starting a family or investing — so you end up matched with a mortgage that fits for years, not just for today. A proper affordability assessment saves a great deal of time and disappointment by steering you away from options you were never going to qualify for. If you are looking to refinance, our refinance mortgage calculator can show you what your monthly costs would look like on a lower rate.
Why a Specialist Broker Matters for Complex Cases
In 2026, a broker with genuine experience of expat clients or other complicated cases is still essential. They understand how to present foreign income and know which lenders take the most flexible view of it. They help you gather the right documentation and present it professionally, and that insider knowledge improves your chances in a competitive market.
If an application is declined, your broker can suggest alternative lenders or challenge the decision — the FCA’s CP26/18 proposals also cover how lenders should assess credit-impaired borrowers, which may open up more options here over time. A broker’s negotiating relationships with lenders matter in the current climate, and they can also advise you on remortgaging or switching lenders later to make sure you continue to get the best rate available to you.
Conclusion
Good mortgage broker advice is worth its weight in gold, even with tighter affordability checks in place. A specialist broker provides real help when your income is complex, and knows exactly how to present your case to the right lenders.
Whether you have overseas income, a short-let investment in mind or bonus-heavy pay, there is a way forward. The key is working with people who understand the system and know how to get the right outcome for your situation. There is no need to let the rules hold you back.
Frequently Asked Questions
What is the FCA stress test and does it still apply in 2026?
Yes, the test itself has not gone away.
Lenders still have to check your mortgage would hold up if rates climbed, usually modelled at around three percentage points above the rate you are offered. What moved is how rigidly the FCA insists that margin gets applied — after its review in December 2025, lenders were given more room to be flexible now that rates sit lower than a couple of years back, which is why two lenders can land on quite different affordability figures for the same application.
Has the Consumer Duty made getting a mortgage harder?
Not really.
The Consumer Duty has been part of FCA regulation for three years now, since July 2023, so by 2026 it is just how lenders work rather than a fresh obstacle. What we see in practice is lenders asking more questions to satisfy themselves a mortgage genuinely suits your circumstances — that can add a day or two to an application if your paperwork is thin, but it does not make a well-prepared case harder to approve.
How much of my bonus will lenders actually count?
This differs sharply from lender to lender.
Some will use roughly fifty per cent of your average bonus over the last two years, while others are much more cautious and want a longer track record before touching it at all. We had a client whose bonus made up most of their income, and the borrowing offers from different lenders were tens of thousands of pounds apart, simply because of how each one treated that bonus.
Can I get a mortgage if I am paid in a foreign currency?
Yes, though the list of lenders willing to consider it shrinks.
Some mainstream banks simply will not touch foreign-currency income, whereas specialist and expat-focused lenders reduce the income they count to allow for exchange rate movement rather than turning the application down outright. A broker who handles these cases regularly knows which lenders currently have an appetite for it, since that appetite changes more often than most other lending criteria.
Do I need extra evidence for a short-let buy-to-let mortgage?
Generally yes.
Most lenders want a realistic rental projection rather than a rough Airbnb estimate, and some will fall back on a standard long-term tenancy figure unless you can demonstrate the short-let income is genuinely achievable. Evidence such as comparable bookings, a seasonal breakdown, or confirmation from your letting agent all count towards a stronger application.
Why does a broker's affordability check differ from an online calculator?
A calculator is a reasonable starting point, but it misses lender-specific detail.
It cannot factor in a specific lender’s stress margin, how they treat bonus income, or foreign earnings the way a proper broker assessment can. Clients regularly turn up with a calculator number that sits £20,000 to £40,000 above what any real lender ends up offering once their actual circumstances are put in front of an underwriter.
What is the FCA's mortgage rule review and could it make things easier for me?
CP26/18 is the FCA’s live consultation on the mortgage rules.
It covers variable and irregular income, foreign currency mortgages and credit-impaired borrowers among its focus areas — the exact situations this article deals with. Responses closed in July 2026 and a policy statement is due later in the year, so none of it is confirmed yet, but it is one to watch if any of those apply to you.
Speak to an Affordability Specialist
If your income does not fit neatly into a standard lender’s affordability model, do not assume you have no options. Talk to us about your bonus, foreign currency or short-let income and we will tell you honestly which lenders are likely to work for you.
UK Mortgage Broker is a whole-of-market broker helping clients throughout the UK and globally to secure funding on UK property. We are directly authorised and regulated by the Financial Conduct Authority.
Your home may be repossessed if you do not keep up repayments on your mortgage.
Call: +44 1628 969 500 Email: info@uk-mortgagebroker.co.uk
Related Pages
- Mortgage Affordability UK Explained — how lenders actually decide what you can borrow, beyond simple income multiples.
- Complex Income Mortgages — specialist help for bonus, foreign or fluctuating income when lenders want a clean paper trail.
- Self-Employed Mortgages — mortgage advice tailored to self-employed and freelance borrowers with variable income.
- Buy-to-Let Mortgages — buy-to-let mortgage advice, including lenders who accept short-let and holiday-let rental income.
- Why Mortgages Get Declined — common reasons UK mortgage applications are declined and how to fix them before you reapply.