Mortgages · for UK homeowners whose fixed-rate mortgage deal is ending
RateCliff is a remortgage countdown for UK homeowners whose fixed-rate mortgage deal is coming to an end. You type four numbers from your own paperwork: the date the fix ends, the balance, your fixed rate and your lender's standard variable rate (SVR). It counts the days left, uses the standard repayment formula to show how much more a month the SVR would cost, and sets out checkpoints 180, 90 and 30 days before the end date. If that date has already passed, a counter adds up what the SVR has cost since then, once a day.
Save your four numbers and the counter lights up straight away. Before your fix ends it is a projection, and says so: how much more a month the SVR would cost, and roughly how much a day once the deal ends. After the end date it counts the real days on the SVR and moves up once a day, with the rate you entered and the date you entered it printed underneath. Mark the switch done and it stops.
The home screen is a track running to the day your fix ends, with markers at 180, 90 and 30 days out. Passed checkpoints are ticked, today has its own marker, and the next job is spelled out with its date and the days left. The monthly figure sits right below it, next to the two payments it came from.
Each checkpoint holds a few plain jobs: start looking and ask your lender about a product transfer at D-180, choose a deal and apply by D-90, confirm the new rate starts the day after the fix ends at D-30. Every item has one line on why it sits there, and the list opens with a reminder that your lender's or broker's guidance comes first.
The end date of a fix usually sits in the mortgage offer, an annual statement or a letter from the lender. MoneyHelper notes that introductory deals normally last between two and five years, and that once a deal ends you will probably be moved onto your lender's standard variable rate, which is usually higher than other rates you might get. The date sits in a drawer for years and then arrives all at once.
UK Finance expected around 1.8 million fixed-rate mortgages to reach the end of their fixed period in 2026. MoneyHelper's advice is to set a reminder to start shopping around at least six months before a fixed or discount deal reverts to the SVR. A calendar reminder gives you the date. It does not tell you what the SVR would cost on your balance, or what has to happen between now and then.
RateCliff works out two monthly payments from the same balance and remaining term: one at your fixed rate and one at the SVR you entered, using the standard repayment formula with interest worked out monthly. The difference is the monthly figure. The daily figure is that difference times 12, divided by 365.25. For an interest-only mortgage it uses balance times rate divided by 12 instead. A How it's calculated page in Settings lists the formula, the assumptions and every number you typed.
The SVR is the one number the app will not guess. Each lender sets its own, and an average says little about yours: the Bank of England's average quoted revert-to rate was 6.58% in August 2026, and it changes from month to month. You copy your lender's figure from its website or your statement, the counter shows that rate and the date you entered it on the same screen, and after 90 days the app asks you to check it is still current. Your lender's own figure can differ by a few pounds depending on how it charges interest, so the counter is labelled as an estimate.
Nothing ticks by the second. The counter changes once a day, when the date changes, and every figure that shows a cost has the next step printed beside it.
Checkpoints are counted back from your end date. D-180 is where MoneyHelper suggests you start shopping around, and it is also when you can usually act: lenders that signed the government's Mortgage Charter let customers lock in a new deal up to six months before a fixed rate ends and ask for a better like-for-like deal until it starts, according to the FCA. D-90 is the app's marker for choosing a deal and applying. D-30 is the last check that the new rate starts the day after the old one ends.
Reminders arrive at each checkpoint, a week before the end date and on the day itself. They are worded so nothing private shows on a locked screen: no balance, no rate, no amount. Change any number later, the end date included, and the countdown, the counter, the checkpoints and the reminders are all worked out again, with your ticks kept.
Not everyone notices before the first higher payment, and the app is built for that too. Enter an end date in the past and RateCliff opens a different home screen. The counter shows the real total since the end date and moves up once a day, and the checkpoints are replaced by a shorter track that starts today: look for a deal, get an offer, switch.
The tone stays level. MoneyHelper notes there are usually no penalties for leaving an SVR, and the card under the counter says it is not too late, with the next step and a link to MoneyHelper's free guidance that opens in your browser. When you have switched, mark it done and the counter stops where it is.
It does not look up rates, compare deals, rank lenders or pass you to a broker, and it has no field for a phone number or an email address. The only comparison it makes is your fixed rate against your own lender's SVR. There is no account and no server, the app sends nothing over the network, and there is no analytics code inside it. One setting deletes everything, scheduled reminders included.
RateCliff is a calculation and planning tool. It is not financial advice and does not recommend any lender, broker or mortgage deal. Before you decide, talk to your lender, an FCA-registered mortgage broker or adviser, or MoneyHelper, which gives free, impartial guidance.
On your lender's website or your mortgage statement, or by asking the lender. RateCliff never fills it in for you, because each lender sets its own rate and an average would give you someone else's number. If the rate changes, edit it and everything is worked out again.
It calculates the monthly payment at your fixed rate and at your SVR with the standard repayment formula, using the same balance and remaining term (25 years unless you change it), and shows the difference. The daily figure is the monthly difference times 12, divided by 365.25. It is an estimate, and your lender's figure may differ by a few pounds.
No. It is not financial advice, and it does not compare products, rank lenders or connect you with a broker. It shows your dates, the cost of the SVR as a calculation and the general steps. For advice, talk to your lender, an FCA-registered broker or adviser, or MoneyHelper.
No. There is no account and no server, and the app makes no network requests. Everything stays on your phone, and Delete all data in Settings removes it along with any scheduled reminders.
Yes. Enter the past end date and the home screen shows what the SVR has cost since then, a short track that starts today and the next step. When you have switched, mark it done and the counter stops.
Under the Mortgage Charter, signatory lenders let customers lock in a new deal up to six months before their fixed rate ends and request a better like-for-like deal until it starts, according to the FCA. MoneyHelper says you can usually apply for a new mortgage up to six months before you need it. Ask your own lender what it allows.
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