Start about six months before your buy-to-let fixed rate ends, and settle one decision early: a product transfer with your current lender or a full remortgage to a new one. If you fixed for five years in February 2022, the average five-year buy-to-let rate has nearly doubled since, so the monthly interest on a £180,000 interest-only loan goes from £474 to about £902; in the example below, TMW's revert rate would cost more than the £1,200 monthly rent.
The backdrop as of 22 October 2026: Bank Rate is 3.75% after the Bank of England's 6 to 3 hold on 17 September, with three members voting for 4% and the next decision due on 5 November (Bank of England). CPI inflation rose to 3.5% in the year to September, up from 3.1% (ONS, 21 October 2026). The Budget is on 28 October and has not happened yet. The general process is in our remortgaging guide.
What rate did your 2027 fix start at, and what replaces it?
A five-year fix taken in 2022 averaged anywhere from 3.16% in February to 6.05% in October, and a two-year fix taken in 2025 roughly 4.9% to 5.2%. It is replaced by whatever you fix next, at reported averages of 5.63% for two years and 6.01% for five, or by the lender's revert rate if you do nothing. Moneyfacts averages across all loan-to-value bands:
| When you fixed | Product | Average rate then | Source |
|---|---|---|---|
| February 2022 | Five-year fix | 3.16% | Moneyfacts |
| May 2022 | Five-year fix | 3.56% | Reported by Mortgage Solutions |
| October 2022 | Five-year fix | 6.05% | Moneyfacts |
| March 2025 | Two-year fix | 5.24% | Moneyfacts |
| September 2025 | Two-year fix | 4.88% | Moneyfacts |
Moneyfacts' own tables use the first available day of each month; the May 2022 figure was reported on 23 May. The current 5.63% and 6.01% are Moneyfacts data reported by PropertyWire on 14 October 2026, which we could not confirm on Moneyfacts' own pages; our October rates update has the detail.
So a landlord on the February or May 2022 five-year averages shown above faces a jump of about 2.5 to 3 points to the reported five-year average, while one who fixed in October 2022 may roll onto roughly the same rate. Two-year fixers on the March or September 2025 averages face a rise of about 0.4 to 0.75 points to the reported two-year average.
If you do nothing, you move to the lender's revert rate. We could not find a public Moneyfacts average buy-to-let revert rate, so here is one lender's own figure: The Mortgage Works (TMW) reverts its 75% LTV buy-to-let products to its managed rate, currently 8.24%, in its switch rate guide effective 1 October 2026.
When should you start if your fix ends in 2027?
Six months before the end date, because that is how long a new remortgage offer lasts at lenders such as TMW and Barclays. Count back from the date on your offer or annual statement:
| When | What to do |
|---|---|
| 6 months before | Find the exact fix end date and the date the early repayment charge (ERC) stops. Check the balance, a realistic value and your LTV band. Run your rent through the remortgage mode of our mortgage calculator. Decide whether you need to raise money. |
| 5 to 4 months before | Apply for a full remortgage if you are moving lender, so the offer is in hand well before the end date. Gather the tenancy agreement, tax calculations and, with four or more mortgaged properties, a portfolio schedule. |
| 4 to 3 months before | Product transfer windows open: NatWest from four months, TMW and Accord from about three. Ask your lender for its switch rates and compare them with any remortgage offer on total cost, not headline rate. |
| 1 month before | Book the switch, or set the remortgage completion for the first day after the ERC period ends, so no charge applies. Check the offer will not expire first. |
| End date | The new rate starts. Check the first payment and that no days were charged at the revert rate. |
| After | Record the new fix end date and ERC schedule, and start the next six-month countdown in your diary. |
The lender windows, read on 22 October 2026:
| Lender | Product transfer window | New remortgage offer valid for |
|---|---|---|
| NatWest | 4 months before the deal ends | Not checked |
| TMW | 13 weeks before the new product starts | 6 months from the first offer, plus a 15-day grace period (criteria) |
| Accord | 90 days before the product ends | Not checked |
| Barclays | Not checked | 6 months from the date the application is received |
Do not complete a remortgage early just because a rate elsewhere looks good. ERCs on many fixes are stepped: TMW's current five-year switch products charge 5% in the early years falling to 1% in the last, and its two-year products 2% then 1%. On a £180,000 balance, even 1% is £1,800.
Product transfer vs remortgage on a buy to let: which should you choose?
Take the product transfer if your lender's switch rate is competitive and you need no extra money; remortgage if you want to raise capital or a better rate elsewhere outweighs the fees and legal work. The differences that decide it:
| Product transfer | Full remortgage | |
|---|---|---|
| Rental (ICR) test | None at TMW (no affordability or credit checks) or NatWest (no additional underwriting on a standalone switch) | Yes, at the new lender's ratio and stress rate |
| Raising extra money | Possible alongside the switch at NatWest, subject to underwriting | Yes, subject to the rental and LTV tests |
| Valuation | Automated (TMW); higher of current valuation or house price index (NatWest); house price index (Accord) | A valuation for the new lender |
| Legal work | None | Solicitor needed |
| Speed | Usually quicker: no valuation visit or legal work | Slower: valuation, underwriting, legal work |
| Four or more mortgaged properties | No fresh underwriting on a standalone switch (NatWest) | Portfolio underwriting when you raise capital; some lenders skip it for like-for-like |
| Rate choice | Your lender's existing-customer range only | Whole market |
Two rules matter more than they look. First, paragraph 1.4 of the Prudential Regulation Authority's SS13/16 exempts like-for-like buy-to-let remortgages from the minimum underwriting expectations in paragraph 1.2(a); arrangement fees, professional fees and administration costs can be excluded when checking for extra borrowing. Lenders still assess whether you can pay. TMW stresses a like-for-like remortgage on any fixed term at the higher of 4.50% or the pay rate above 65% LTV, but a two-year fix that raises capital at the higher of 5.50% or the pay rate plus 2 points (TMW income criteria). NatWest skips its portfolio check for like-for-like remortgages (NatWest criteria).
Second, with four or more mortgaged buy-to-lets you are a portfolio landlord under SS13/16, and a lender raising capital for you can look at the whole portfolio. Limited companies have narrower choice: Barclays does not offer new limited company buy-to-let mortgages, while TMW tests a company like-for-like remortgage at the higher of 4.50% or the pay rate.
What does a BTL remortgage calculator show for a fix taken in 2022?
On our example, the monthly interest nearly doubles, and a higher-rate landlord at a 145% ratio fails a fresh rental test that a basic-rate landlord passes. The assumptions: a £180,000 interest-only loan fixed for five years in February 2022 at 3.16%, the Moneyfacts average then; the property is worth about £250,000 (72% LTV) and lets for £1,200 a month.
Monthly interest is loan x rate ÷ 12:
| Option | Rate | Monthly interest | Change vs 2022 |
|---|---|---|---|
| 2022 five-year fix | 3.16% | £474.00 | |
| Average two-year fix now | 5.63% | £844.50 | +£370.50 |
| Average five-year fix now | 6.01% | £901.50 | +£427.50 |
| Do nothing: TMW managed rate | 8.24% | £1,236.00 | +£762.00 |
Drifting onto the revert rate costs £334.50 a month more than the average five-year fix, £4,014 a year, and the interest alone is £36 a month more than the rent.
Your own lender may beat the averages. TMW's 1 October switch guide offers existing customers a five-year fix at 75% LTV of 5.24% with no fee (£786 a month) or 4.64% with a 3% fee (£696 a month plus £5,400). Over five years both come to £47,160 on this loan, before any interest on an added fee, so the fee buys nothing here. Compare total cost, not the headline rate.
Now the rental test. The 125% and 145% ratios are Barclays' basic-rate and higher-rate figures; the stress rules are TMW's published ones, applied to the reported average rates. This illustrates the maths, rather than a single lender's offer. Rent of £1,200 a month is £14,400 a year, and rent needed is rounded to the nearest pound:
| Test | Stress rate | Stressed annual interest | Cover achieved | Rent needed at 125% | Rent needed at 145% |
|---|---|---|---|---|---|
| Like-for-like, two-year fix | 5.63% (pay rate) | £10,134 | 142.1% | £1,056 | £1,225 |
| Like-for-like, five-year fix | 6.01% (pay rate) | £10,818 | 133.1% | £1,127 | £1,307 |
| Raising capital, two-year fix | 7.63% (pay rate + 2) | £13,734 | 104.8% | £1,431 | £1,660 |
A basic-rate landlord passes either like-for-like test. A higher-rate landlord at 145% fails both, by £25 a month on the two-year and £107 on the five-year; at TMW's own 160% higher-rate ratio the rent would need to be £1,351 and £1,442. Raising capital on a two-year fix fails at both ratios. Raising capital on a five-year fix is tested at the pay rate, so it matches the like-for-like five-year row.
Note the twist. On a like-for-like remortgage both terms are tested at the pay rate, and with five-year fixes now dearer than two-year ones, the two-year passes more easily. The usual advice that a five-year fix helps affordability, covered in our ICR guide, holds mainly when you raise capital.
Does the April 2027 tax rise change the lender's sums?
Not in the criteria checked here: as of 22 October 2026, the Barclays and TMW pages and SS13/16 do not specify new interest cover ratios for the higher property income rates due from 6 April 2027. The Budget on 28 October 2026 set those rates at 24%, 44% and 49% in England, Wales and Northern Ireland, up from the 22%, 42% and 47% in Finance Act 2026, with finance cost relief at 24%, to be legislated in Finance Bill 2026-27 (Budget 2026, para 6.246; policy costings, page 74). SS13/16 does expect lenders to take tax, including mortgage interest relief, into account (paragraph 2.6), so watch for criteria updates.
The cash-flow effect in this example is modest. The tax rate on the rent rises 4 points and so does the credit on the interest, so with no other costs, the full credit available and all the rent taxed in one band, the extra tax is 4% of (rent minus interest). On our example at 6.01%, that is 4% of £3,582, or £143.28 a year, in the basic, higher or additional band alike, against £71.64 at the Finance Act 2026 rates. Our 2027 property income tax guide has the full rules and our Autumn Budget 2026 guide the announcement. Scotland is treated separately, and Finance Act 2026 gives Scotland and Wales powers to set their own property rates, in force since 16 September 2026 for 2027-28 onwards (SI 2026/1023). Check the applicable rates where you pay tax.
What if the numbers no longer pass?
If eligible, compare a switch with your current lender first: a standalone product transfer needs no fresh rental test at TMW or NatWest, so failing a new lender's ICR need not trap you on the revert rate. Other levers:
- Borrow less. At 145%, the rent supports £176,394 on the like-for-like two-year fix and £165,241 on the five-year, so you would need to pay down £3,606 or £14,759. Loan ceilings are rounded down to whole pounds and paydowns up.
- Use your salary. Some lenders let earned income cover a rental shortfall; see top slicing explained. TMW and NatWest do not.
- Don't raise capital at the switch. A like-for-like remortgage gets the gentler test; at TMW, raising capital or a further advance on a two-year fix is tested at the higher of 5.50% or the pay rate plus 2 points.
- Fix for five years if you must raise capital. In our example the test drops from 7.63% to the 6.01% pay rate, lifting the 145% ceiling from £130,157 to £165,241.
- Raise the rent, honestly. Lenders use a valuer's figure or the tenancy in place, not your target.
- Sell. If the property only works at 2022 rates, price the sale, including capital gains tax, against years of thin or negative cash flow.
Run your own figures through the calculator above at six months out, then again when offers arrive. The rate you lock in sets your cash flow for the next two to five years.
General information, not legal, tax or financial advice. Lender criteria and Bank Rate were read on 22 October 2026 and averages are as reported on the dates given; they change often, so speak to a whole-of-market broker before you commit.
