Intelligent Rebalance
Our calculator lets you work out the mortgage interest saved vs index return to educate you on where to place the overpayment.
Smart Mortgages, Smarter Investing. Overpay your mortgage or invest? See both.
nume helps homeowners pay off debt smarter while building long-term wealth, all balanced in one intelligent app. If you invest, your capital is at risk.
Already know what you want? Download the app
Illustrative app screen using example data. Past performance is not a reliable indicator of future results.
What is nume?
nume provides tools to help homeowners understand and compare mortgage overpayments and investing. It offers a property valuation tool, an overpay-versus-invest calculator and the Mortgage Freedom Pot, a Stocks and Shares ISA. A General Investment Account is also available. Capital at risk.
Recognised by
- London winner, Innovate Finance Pitch360 2025
- Developed at the London Business School Entrepreneurship Summer School
- Showcased at Barclays Demo Day
Partners
Stop guessing. Start optimising.
Manage the trade-off between mortgage payoff and investing with data, not guesswork.
Uncap Your Wealth
Invest in low-cost index funds for the potential for long-term returns instead of keeping all your wealth tied up in property.
Flexible Control
Funds are held in liquid ETFs, offering quicker access than property equity, though investment values fluctuate.
As with all investments, your capital is at risk. The value of both property and ETFs can go down as well as up, and you may get back less than you invest.
Mortgage-free date
When could you be mortgage-free?
Enter your mortgage. See the date you clear it, and how much sooner that date moves when you put your spare each month to work. No guesswork, just the maths.
Try the calculatorIllustrative example: £300,000 outstanding at 4.5%, 22 years left, £400 a month spare. Investment outcomes are shown at assumed returns of 5%, 2% and -2% a year, after nume's 0.40% platform fee.
Forecasts are not a reliable indicator of future performance.
Your current plan-
Overpay your spare-
Invest it in a nume pot at 5% a year-
Invest it in a nume pot at 2% a year-
Invest it in a nume pot at -2% a year-
Fund management fees are not included and would reduce returns.
Capital at risk. Overpaying is a guaranteed saving on interest; investing is not.
The Smart Trade-Off
Balancing mortgage payoff with long-term investing.
Financial Flexibility
Traditional Payoff
✗Money locked in your property can’t easily be accessed or invested elsewhere.
nume
✓Funds in your investment can usually be accessed quickly, though their value may decline.
Wealth Maximisation
Traditional Payoff
✗You may miss out on potential compound growth from long-term market investments.
nume
✓Benefit from the potential compound returns of diversified investments.
Diversification
Traditional Payoff
✗Your home is a single asset class and not easy to turn into cash when you need it.
nume
✓Spreads risk across your property debt and diversified index funds.
Investing may offer the potential for higher returns, but keeping your mortgage for longer means paying more interest overall, and tax treatment will depend on your individual circumstances.
4 Steps to Financial Balance
We make financial plans accessible with smart tools that help you explore and manage your options.
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Setup
Securely link your mortgage or enter the details. Choose your financial goals: quicker payoff, bigger investments, or both.
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Compare
nume provides a calculator so you can see how different choices might affect your future wealth compared with overpaying only.
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Automate
Pick your plan. You keep paying your mortgage to your lender as normal. We help you set up monthly transfers into your investment account (index funds), and you decide whether to overpay your lender.
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Track
Monitor your progress in one dashboard. If interest rates or your circumstances change, you can update your plan and the projections will adjust automatically.
Fees
What are the fees?
For customers who open an account with nume, we charge no monthly subscription fee and a yearly platform fee of 0.40% of your investment value (billed monthly). Additional fund management fees depend on the fund/ETF selected (outlined in the KIID).
0.40%yearly platform fee, billed monthly
- Monthly subscription fee
- None
- ETF trading fee
- None
- Fund management fees
- Depend on the fund/ETF selected (outlined in the KIID)
Regulation
Your financial security and transparency are our top priorities.
Regulation
nume is an Appointed Representative of RiskSave Technologies Ltd, which is authorised and regulated by the Financial Conduct Authority.
Protection
If you open an ISA account, your eligible cash and assets held with our custodians may be protected by the Financial Services Compensation Scheme (FSCS) up to £85,000.
If you open a GIA account, your cash and assets are held with Interactive Brokers LLC (IBKR US) and are protected by the Securities Investor Protection Corporation (SIPC) up to US $500,000 (including US $250,000 for cash), with additional excess coverage provided by Lloyd’s of London.
*This protection does not cover losses due to changes in investment value.
Learn
Guides for homeowners
Mortgages
Should I overpay my mortgage or invest?
How to weigh a guaranteed saving on mortgage interest against the potential, but uncertain, growth from investing, with a worked example.
4 min read
Remortgaging
What happens when your fixed rate ends?
What happens when your fixed mortgage rate ends: the three options, what could happen to your payment and when to start looking. A plain-English guide for UK homeowners.
2 min read
Mortgages
How much can you overpay your mortgage each year?
Many UK lenders allow up to 10% a year without a charge. See how overpayment limits work, what early repayment charges apply and how to check yours.
2 min read
nume in the press
nume has been featured in the national and regional press.
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Nume partners with OneDome to pilot mortgage-tracked ISA
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'Small payment' can 'save thousands and shave years off' mortgages
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Mortgage method could 'shave years off' with 'small payments'
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Sprout named London winner of UK-wide Pitch360 from Innovate Finance
These articles are written by third parties, and the views in them are not nume's advice or recommendations.
FAQ
What is nume?
nume provides tools to help homeowners understand and compare mortgage overpayments and investing. It offers a property valuation tool, an overpay-versus-invest calculator and the Mortgage Freedom Pot, a Stocks and Shares ISA. A General Investment Account is also available. Capital at risk.
Is nume financial advice?
No. nume provides tools that show different scenarios and trade-offs between overpaying and investing. It does not tell you what to do. If you want personal advice, speak to a regulated adviser.
What are the fees?
For customers who open an account with nume, we charge no monthly subscription fee and a yearly platform fee of 0.40% of your investment value (billed monthly). Additional fund management fees depend on the fund/ETF selected (outlined in the KIID).
Do I still pay my mortgage normally?
Yes. You always make your required payments directly to your lender. nume focuses on optimising the extra amounts you choose to pay, helping you decide whether to overpay or invest. Your home may be repossessed if you do not keep up repayments on your mortgage.
Should I overpay my mortgage or invest?
It depends on your mortgage rate, how long is left on your fixed rate, your loan to value ratio, your tax position and how comfortable you are with risk. Overpaying can reduce your balance and the interest you pay, but it ties money up in your home. Investing offers the potential for growth and may keep your money easier to access, but its value can fall and you may get back less than you put in. nume's calculator shows both side by side using your own numbers. Capital at risk.
Is my money protected?
Your money and assets are held with Interactive Brokers in segregated accounts, separate from the firm’s own funds. If you open an ISA account, your eligible cash and assets held with our custodians may be protected by the Financial Services Compensation Scheme (FSCS) up to £85,000. If you open a GIA account, your cash and assets are held with Interactive Brokers LLC (IBKR US) and are protected by the Securities Investor Protection Corporation (SIPC) up to US $500,000 (including US $250,000 for cash), with additional excess coverage provided by Lloyd’s of London. This protection does not cover losses due to changes in investment value.
Unlock your home's potential.
Join homeowners optimising their mortgage and accelerating wealth.
If you invest, your capital is at risk.
Get the nume App