Shared Ownership Mortgage Calculator for London
London shared ownership has its own rules: a £90,000 household income cap, shares from 10%, and rent on the unsold share that can top £1,000 a month. Enter the price, your share, deposit, rent and service charge and see what 32 lenders could lend on your share, with the rent counted the way they count it.
Lender criteria last reviewed September 2026.
Check My London Shared Ownership BorrowingFree. About 5 minutes. No credit search.
Still browsing listings? Run it on the home you like most. The answer gives an estimate of whether the share falls within lenders’ published limits.
What a London share costs over the years
Rent, service charge and mortgage together, year by year, starting from a £450,000 London home with a £250 a month service charge. Change the numbers to match the listing.
Share value £112,500
5% of your share
Your figures
Illustration, not a personal recommendation- Total spend over 25 years
- £655,098
- First-year monthly cost
- £1,696
- Share owned at the end
- 25%
- Equity at the end
- £184,568
Assumes a 5.75% mortgage over 25 years, a lease signed now, with rent rising CPI + 1% (CPI at a long-run 2%), and house prices growing 2% a year (they can fall). Change any of these, add staircasing and compare with renting in the full calculator.
Open the full calculatorWhat is different about shared ownership in London
A £90,000 income cap
Household income must be £90,000 or less in London, against £80,000 elsewhere in England. There is no cap on the property price, so a £600,000 or £800,000 home can still be bought through the scheme.
Rent on the unsold share decides it
At around 2.75% a year of the part you do not own (up to 3% on new homes, sometimes more on resales), London rent is often larger than the mortgage payment. Lenders deduct it, and the service charge, before they set your maximum loan.
Fewer lenders, each with its own share limit
32 of the 57 lenders we check lend on shared ownership. Some only lend from a 25% share and each caps its loan at its own percentage of the share value.
Before any lender looks at it, the housing association’s adviser works out the share you can afford. Under the GLA’s Capital Funding Guide, your total housing costs (mortgage, rent and service charge) should normally be no more than 40% of your net household income. Going above that needs the adviser and the lender to agree, and the housing association to approve it.
Two London examples
Both use the figures a listing on Share to Buy, Homes for Londoners or a housing association’s own site gives you: full price, the share on offer and the monthly rent, plus the service charge from the Key Information Document.
A typical first share: £600,000 flat, 25% share
- Share value £150,000, 5% deposit on the share £7,500, mortgage needed £142,500
- Rent on the £450,000 unsold share at 2.75% a year: about £1,031 a month
- Service charge, say £250 a month
The mortgage is modest. The £1,281 a month of rent and service charge is what the lender tests you against, and it is why this case turns on lender choice as much as salary (it passes the GLA’s 40% guideline for two earners on £90,000 between them, but only just fails it for a single £90,000 earner).
At the ceiling: £800,000 home, 40% share
- Share value £320,000, 10% deposit on the share £32,000, mortgage needed £288,000
- Rent on the £480,000 unsold share at 2.75% a year: about £1,100 a month
- Service charge, say £300 a month
A £288,000 loan under the £90,000 income cap, with £1,400 a month deducted first, sits close to most lenders’ limits. A handful will do it and most will not. On a £90,000 household income (about £6,000 a month after tax and NI for two £45,000 earners), the mortgage, rent and service charge here come to about £3,000 a month. That is around half of take-home pay and well above the GLA’s 40% guideline, so the housing association would normally steer you to a much smaller share (about 10-12% at this price) unless it approves an exception. The lender test comes second.
Worked maths from the scheme’s typical 2.75% rent basis, not a live lender run. Run the tool with your own figures for the lender-by-lender answer.
What you will need
- The full purchase price of the home
- The share you are buying (10% to 75%)
- Your deposit — on the share, not the full price
- The monthly rent on the unsold share
- The monthly service charge, which on London flats is often £150 to £400
- Your income and any credit commitments
Buying outside London? Use the national shared ownership calculator. For the two-stage assessment and the income rules, read the shared ownership affordability guide.
Run My London Shared Ownership CheckFrequently asked questions
Is the shared ownership income cap different in London?
Yes. To buy through shared ownership your household income must be £90,000 or less in London, against £80,000 or less elsewhere in England. It is gross household income, so salary, self-employed profit, regular overtime and bonuses all count. There is no cap on the property price, which is why London shared ownership homes can be listed at £600,000 or more.
What is the minimum share I can buy in London?
New-model leases, which cover most homes built or first sold since 2021, let you buy from a 10% share. Older leases usually start at 25%. Lenders set their own minimums too. Barclays, Nationwide, Santander, Skipton, TSB and Virgin Money only lend from a 25% share (Santander needs 50% in Northern Ireland), and Halifax needs 25% on a resale or 20% on a new build. A few, such as Leeds Building Society, lend from 10%. The check doesn't yet screen lenders by minimum share, so if you're buying less than 25%, confirm each lender's minimum before relying on its figure.
Why is the rent such a large part of the London calculation?
Because it is charged on the share you do not own, and in London that is a big number. Rent on a new home is usually 2.75% a year of the unsold share (the limit is 3%), so on a £600,000 home where you buy 25% the rent is around £1,031 a month before the service charge. On a resale it starts at whatever the previous owner was paying. Lenders deduct that as committed spending before they work out your maximum loan, which is why two people on the same salary can get very different answers depending on the share and the price.
Does the calculator work for resale shared ownership homes in London?
Yes. The maths is the same: share value, deposit on the share, rent on the rest and the service charge. On a resale the lease may be an older one, which usually means a 25% minimum share and rent that has been rising with inflation, so check the current rent on the listing rather than the original figure.
Does it run a credit check?
No. It uses lenders' own published affordability calculators and criteria, with no credit search and no application.
Do I need a mortgage adviser for shared ownership in London?
In practice, yes. The housing association asks for a financial assessment from a qualified adviser before it accepts a reservation, and in London the lender choice matters a great deal because the rent and service charge push most cases close to a lender's limit. This tool gives you the lender answer to take into that conversation.
Results are indicative and based on lenders’ published calculators. They are not a mortgage offer or advice.
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