CIS Mortgage Calculator
YOUR HOME MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON YOUR MORTGAGE.
Most buy to let mortgages are not regulated by the Financial Conduct Authority
Podcast approved by The Openwork Partnership on 06/03/2025
CIS Mortgage Calculator
David Sharpstone talks to us all about CIS Mortgage Calculators and whether they can be helpful.
Should I use a CIS Mortgage Calculator?
Strictly speaking, there isn’t such a thing. There are a lot of online mortgage calculators that can work out how much you can borrow. However, they’re very generic, and every mortgage lender has their own way of calculating things.
As an example, perhaps you work as a CIS subcontractor and you earn £200 pounds a day before tax, and you always work five days a week. You could put your income into a very generic calculator at £1,000 a week and £52,000 a year. You might even get an answer from a calculator that resembles the truth around what you can borrow.
But in reality, I would avoid using any online calculators that suggest they are CIS mortgage specific, unless it’s on a particular mortgage lender’s website. In that case, that calculator will only confirm how that lender will assess your income.
As I said, every lender is different. So avoid CIS mortgage calculators and speak to a human being instead. Well, not any human being – not ‘Trevor at the pub’ – talk to an experienced mortgage advisor that is used to dealing with CIS subcontractors.
We understand all the lenders, how they assess your income and how your recent income fits in with their affordability model.
Will a mortgage calculator show me all the rates available with different lenders?
There are lots of calculators out there on different comparison websites, and sometimes on mortgage lenders’ websites. It depends where you end up.
As I said in the previous question, take anything that says it’s a CIS mortgage calculator with a pinch of salt. Unless it’s on a specific mortgage lender’s website, it will give you a very generic answer that could be £100,000 off from reality – in either direction.
Some calculators will tell you the rates from different mortgage lenders. But again, be careful because only 15% to 20% of mortgage lenders use CIS gross payslip income to calculate affordability. You could potentially be shown a rate you can’t have – because it doesn’t fit with how you’re paid.
Do CIS mortgage calculators take into account fluctuating income?
Not unless the calculator specifically asks about your income for the last 13 weeks, and makes an assessment off the back of that. That would take into account any fluctuations.
But if it just wants a generic number around how much you earn, then no, it doesn’t account for fluctuating income. The answer you get out will only be as good as the information you put into it. That’s the problem with any online calculators, not just CIS ones.
There’s so much variation from lender to lender that the best way is always to speak to a mortgage broker.
Should I use day rates, gross income or a different method when using a CIS mortgage calculator?
My answers to the first three questions basically suggest you should avoid CIS mortgage calculators if you find them online. I don’t have one on my website for exactly that reason.
However, if you insist on getting an idea of how much you could borrow, then it’s best to use your gross day rate, and multiply it by the typical number of days you work in a week, and then how many weeks you expect to work in a year.
But it’s still going to give you the wrong answer. It’s only ever to be taken as a guide, so I would generally avoid it. If you really insist, then do it that way.
Speak To An Expert
What does a lender take into account when looking at affordability for a CIS mortgage that a calculator may not show?
A CIS mortgage calculator will only just give you a very basic guide. It won’t necessarily take into account all your expenses, how many financial dependants you’ve got and all those things.
Plus, the income you’re putting into a generic calculator will be probably wrong. If you’re going direct to a specific mortgage lender’s calculator, it really depends whether that calculator is factoring in that you’re a CIS worker.
Let’s assume that it does. Some high street lenders might ask whether you’re paid through the CIS scheme, and if the answer is yes it could open up a new tab to ask how much you’ve been paid for each of the last 13 weeks. You might get more of an accurate answer out of that.
Something that a lender may account for on their calculator could be how many financial dependents you’ve got, whether that’s children or financially dependent adults. They may also ask how much you owe on credit cards or store cards, and whether they will be paid off before you apply for a mortgage.
They’re also going to include other fixed term finance agreements, whether that’s a loan, car finance, hire purchase or a lease agreement. It can even come down to things like Klarna and PayPal arrangements. Also, they often ask if you’ve got any other mortgages in the background.
Do all CIS mortgage calculators take credit history into account?
With any calculator, whether it’s a CIS mortgage calculator or a very generalised version, there are no credit checks involved. The calculator won’t know what your credit history is like.
Quite often a client comes to me having checked the amount they can borrow online. I then have to inform them that, after looking at their credit history, their borrowing is going to be very limited.
That’s the thing with online calculators. They should only be taken as a guide. I wouldn’t advise making any offers on properties if you’ve only looked at an online calculator.
Do all CIS mortgage calculators take employment history into account?
No, they don’t ask how long you’ve been with the same firm or how long you’ve been a CIS subcontractor. They ask for very limited information. Because of that, there’s a good chance you’d get a result that has no reflection on reality.
Come and speak to a specialist mortgage broker rather than clicking a few buttons and putting in inaccurate income – it’s unlikely that would give you anything useful whatsoever.
Do CIS mortgage calculators take into account additional fees or costs?
No, a CIS mortgage calculator online wouldn’t take into account any costs for solicitors, arrangement fees, survey fees or any other buying costs. It’s just going to give you a broad guide on what you might be able to borrow, not factoring in any additional costs.
What are the benefits of using a mortgage broker when looking for a CIS mortgage?
A calculator is not going to tell you anything useful compared with a mortgage broker that understands CIS pay – that’s really the key thing here.
A mortgage broker not only understands CIS pay but knows the lenders and the nuances from bank to bank – how they operate and how they look at the different aspects of income.
I looked at a client’s file just before we started this recording, where we compared three high street lenders that accept gross CIS pay. There was a difference of £150,000 from one lender to the next in terms of how much they would lend.
If that client went to the wrong lender, they’d be buying a flat in a tower block where the lift probably breaks down. With the right lender, they could afford to buy a house.
That is literally the difference with the wrong lender or the wrong mortgage broker. I hope that demonstrates the benefits.
YOUR PROPERTY MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON YOUR MORTGAGE.
Approved by The Openwork Partnership on 06/03/2025.
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