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PROPERTY WORKSPACE / LETLOGIQ

Buy-to-let stress test: lower rent and higher mortgage rates

See how your rental cash changes when rent falls, interest rises, or both happen together. This is a cash-flow scenario calculator, not a lender mortgage affordability or ICR test.

2026–27 tax basis
Start calculation ↓Jump to stress scenarios ↓Read the guide ↓

Your investment

Illustrative starting inputs

Start here: enter your details
4 stages below. Scroll the fields, then choose Next.

The property basics

Start with the purchase price and a realistic rent.

For context; bedroom count does not predict rent.
£
£
Count residential property worldwide, including applicable spouse / joint-owner interests. Companies use higher rates.
One property let to a single household. First-time buyer relief is not applied to an investment letting.
Tab 1 of 4
Values update your estimate as you type.
Monthly post-tax cash profitLetLogi
£280/ month

£3,357 a year after running costs, mortgage payments and estimated tax.

Pre-tax cash / month£350
Income tax / month£70
Post-tax cash / month£280

Both cash figures are after running costs and mortgage interest only. No capital repayment is deducted. The post-tax figure also deducts estimated tax. Displayed amounts are rounded independently.

FULL-YEAR OPERATING ESTIMATEAfter income tax
Cash-on-cash ROI
4.52%Annual post-tax cash ÷ upfront cash
Upfront cash needed£74,295Includes setup costs & cash reserve
Gross yield · pre-tax7.20%Full rent ÷ purchase price
Net yield · pre-tax, pre-finance5.85%After voids & costs; before finance / tax
LetLogi
YOUR INVESTMENT, REFINED

Start with the pressure points

Change an input. See what improves — and what gives.

34.1OUT OF 100
Rules-based summary

Yield: Your 7.20% gross yield is 0.24 percentage points above the 6.96% overall buy-to-let lender-sample average. Your net yield is 5.85% before finance and tax.

Your money at work: For every £1,000 of upfront cash invested, this property generates approximately £56 a year before tax, after running costs and mortgage payments.

Cash payback: 22 years 2 months under the projection below.

Paragon Bank · Q1 2026 gross yields. Lender sample, not a local market valuation. Standard BTL uses the overall sample, including specialist properties; HMO uses the HMO sample. Gross yield is before costs, finance and tax. Benchmark checked 11 September 2026; not live data.

This scenario leaves £280 a month after tax and mortgage payments. Under your combined custom stress, post-tax monthly cash is -£16. Confirm 16 cost allowances before relying on the score.

Expand score breakdown & comparisonsCollapse score breakdown & comparisons
Compared with your saved point (Standard BTL · personal)+0.0 points
Post-tax cash £0 / month changeUpfront cash £0 change
Net operating yield18.3 / 25+0.0
x
0% → 0 points; 8% or more → 25.
Post-tax cash return11.3 / 25+0.0
x
0% ROI → 0 points; 10% or more → 25.
Combined stress resilience0.0 / 25+0.0
x
Fixed rent −10% / rate +2pp: no surplus → 0; surplus ≥20% of base rent collected → 25.
Borrowing headroom4.5 / 15+0.0
x
90% loan-to-value → 0; 40% or less → 15.
Allowance confirmation0.0 / 10+0.0
x
Share of optional cost fields explicitly entered × 10.
Try a what-if

Temporary assumptions to explore, not suggested rents or offers.

0% of cost allowances entered16 still use planning estimates
How this assessment works

Points update in 0.1-point increments. Financial factors use the same thresholds for both strategies. Scoring always tests rent −10% and interest +2 percentage points (cash purchases have no rate shock), regardless of the custom stress settings below.

Saved comparison inputs last for this page session. Entering an allowance confirms only that you supplied it, not that it is accurate. Location, tenant demand, property condition and legal eligibility are not scored. This is a planning rubric, not a guarantee.

RECOUP YOUR UPFRONT CASH
LetLogi

Post-tax cash payback

%
Applied from year 2. Enter 0 for unchanged rents; range −20% to 20%.
%
Fixed running costs grow from year 2. Management fees follow collected rent; range −20% to 20%.
22 years 2 months

To recover £74,295 of upfront cash, including your opening reserve, from cumulative rental cash after tax.

By the recovery month: £74,412 cumulative post-tax cash — £74,295 repays your upfront investment and £117 is surplus. Monthly cash is averaged within each year.

First full year after recovery · year 24

Scheduled rent / month£1,200
Rent collected / month, after voids£1,154
Post-tax cash profit / month£280
Post-tax cash profit / year£3,357
Expand annual projection · 50 years
YearRent collectedRunning costsMortgage paymentsTaxPost-tax cashCumulative cashSurplus after upfront
1£13,846£2,150£7,500£839£3,357£3,357-£70,938
2£13,846£2,150£7,500£839£3,357£6,714-£67,581
3£13,846£2,150£7,500£839£3,357£10,071-£64,224
4£13,846£2,150£7,500£839£3,357£13,428-£60,867
5£13,846£2,150£7,500£839£3,357£16,785-£57,510
6£13,846£2,150£7,500£839£3,357£20,142-£54,153
7£13,846£2,150£7,500£839£3,357£23,498-£50,797
8£13,846£2,150£7,500£839£3,357£26,855-£47,440
9£13,846£2,150£7,500£839£3,357£30,212-£44,083
10£13,846£2,150£7,500£839£3,357£33,569-£40,726
11£13,846£2,150£7,500£839£3,357£36,926-£37,369
12£13,846£2,150£7,500£839£3,357£40,283-£34,012
13£13,846£2,150£7,500£839£3,357£43,640-£30,655
14£13,846£2,150£7,500£839£3,357£46,997-£27,298
15£13,846£2,150£7,500£839£3,357£50,354-£23,941
16£13,846£2,150£7,500£839£3,357£53,711-£20,584
17£13,846£2,150£7,500£839£3,357£57,068-£17,227
18£13,846£2,150£7,500£839£3,357£60,425-£13,870
19£13,846£2,150£7,500£839£3,357£63,782-£10,513
20£13,846£2,150£7,500£839£3,357£67,138-£7,157
21£13,846£2,150£7,500£839£3,357£70,495-£3,800
22£13,846£2,150£7,500£839£3,357£73,852-£443
23£13,846£2,150£7,500£839£3,357£77,209£2,914
24£13,846£2,150£7,500£839£3,357£80,566£6,271
25£13,846£2,150£7,500£839£3,357£83,923£9,628
26£13,846£2,150£7,500£839£3,357£87,280£12,985
27£13,846£2,150£7,500£839£3,357£90,637£16,342
28£13,846£2,150£7,500£839£3,357£93,994£19,699
29£13,846£2,150£7,500£839£3,357£97,351£23,056
30£13,846£2,150£7,500£839£3,357£100,708£26,413
31£13,846£2,150£7,500£839£3,357£104,065£29,770
32£13,846£2,150£7,500£839£3,357£107,422£33,127
33£13,846£2,150£7,500£839£3,357£110,778£36,483
34£13,846£2,150£7,500£839£3,357£114,135£39,840
35£13,846£2,150£7,500£839£3,357£117,492£43,197
36£13,846£2,150£7,500£839£3,357£120,849£46,554
37£13,846£2,150£7,500£839£3,357£124,206£49,911
38£13,846£2,150£7,500£839£3,357£127,563£53,268
39£13,846£2,150£7,500£839£3,357£130,920£56,625
40£13,846£2,150£7,500£839£3,357£134,277£59,982
41£13,846£2,150£7,500£839£3,357£137,634£63,339
42£13,846£2,150£7,500£839£3,357£140,991£66,696
43£13,846£2,150£7,500£839£3,357£144,348£70,053
44£13,846£2,150£7,500£839£3,357£147,705£73,410
45£13,846£2,150£7,500£839£3,357£151,062£76,767
46£13,846£2,150£7,500£839£3,357£154,418£80,123
47£13,846£2,150£7,500£839£3,357£157,775£83,480
48£13,846£2,150£7,500£839£3,357£161,132£86,837
49£13,846£2,150£7,500£839£3,357£164,489£90,194
50£13,846£2,150£7,500£839£3,357£167,846£93,551

Illustration, not a forecast: rents and fixed costs change once each year; vacancy rates stay constant. Tax is recalculated using fixed 2026–27 rules and unchanged other income, without carrying tax losses or finance relief forward. Repayment mortgages amortise and end at the entered term. Interest-only borrowing is assumed refinanced at the same rate with no fees, leaving the capital debt outstanding. No sale, capital growth or reinvestment is included. Rent increases must be achievable and legally permitted.

LetLogi

Follow the money

Full-year operating cash breakdown. Amounts are rounded independently.

Scheduled rent£14,400
Less empty periods-£554
Rent collected£13,846
Running costs＋ Show cost breakdown− Hide cost breakdown-£2,150
Maintenance & repairs-£1,200
Landlord insurance-£350
Service charge & ground rent-£0
Safety checks & compliance-£300
Accounts & administration-£300
Other allowable running costs-£0
Non-deductible cash costs-£0
Management fees-£0

Includes all running-cost categories; figures are rounded independently.

Mortgage interest-£7,500
Capital repaid-£0
Pre-tax cash profit£4,196
Estimated income / corporation tax-£839
Post-tax cash profit£3,357
Upfront cash & annual tax detail
Deposit / cash purchase£50,000
Purchase tax£11,500
Refurbishment & other setup£7,300
Mortgage & broker fees£2,495
Opening reserve£3,000
Taxable property profit (not cash profit)£11,696
HMO bills & licensing within running costs£0
Personal finance-cost tax reduction£1,500
Unused finance costs to carry forward£0
Property loss (no current tax credit)£0

Repayment principal builds equity but reduces spendable cash. ROI excludes that equity gain and any property appreciation. Purchase costs are not deducted from ongoing rent. Company losses are not set against other profits in this estimate.

Give it a stress test

Monthly post-tax cash

What happens when the assumptions move against you?

%
Reduces total rent collected after your normal vacancy allowance. For an HMO, this covers all rooms together; fixed bills stay unchanged.
pp
Lower rentTotal property rent collected down 10% after the usual vacancy allowance
£187
Higher interestRate up 2 percentage points
£80
Both togetherReduced rent and increased rate
-£16

Each scenario recalculates tax and the first 12 loan payments. A rate increase has no effect on a cash purchase. These are scenarios, not forecasts or lender affordability tests.

Published by LetLogiQ · Page updated 20 September 2026 · Calculation basis & updates

Start with a realistic base case

Enter the rent you expect to collect, normal vacancies, costs and finance terms first. Then use the stress-test panel to choose a rent reduction and an interest-rate increase. The reduction applies after the normal vacancy allowance; avoid accidentally counting the same downside twice.

Test each pressure separately and together

The calculator recalculates tax and the first twelve loan payments for each scenario. An interest-rate increase is entered in percentage points: a rise of 2 points changes a 5% rate to 7%. Cash purchases have no mortgage-rate shock.

Cash-flow stress testing is different from lender affordability

Lenders may use their own stressed rates, interest-cover ratios and underwriting rules. Those criteria are not modelled here. Use these scenarios to explore the resilience of your estimated cash flow, then ask a lender or broker about borrowing eligibility.

Stress-test worked example

This fixed illustration uses the calculator’s starting assumptions, not your edited inputs: England, a £200,000 additional property, £50,000 deposit, 5% interest-only borrowing and a 25-year term. Rent of £1,200 per month, two weeks’ voids and standard operating allowances. Personal ownership, £35,000 other annual income and the England/Wales/Northern Ireland income-tax basis. Remaining costs use the editable planning estimates.

Annual scheduled rent
£14,400
Annual running costs
£2,150
Annual estimated tax
£839
Monthly cash after tax
£280

With the default combined rent reduction of 10% and rate rise of 2 percentage points, monthly cash becomes -£16.

Rounded figures are illustrative. The live calculator above provides the full cost and tax breakdown.

Common questions

Does this tell me how much a lender will lend?

No. This calculator estimates property cash flow under adverse assumptions. It does not apply a lender’s interest-cover ratio or underwriting policy.

Does the stress test recalculate tax?

Yes. Each scenario recalculates the modelled tax and mortgage cash flow. The tax-year assumptions remain fixed.

Can I stress-test an HMO?

Yes. Select HMO and enter room rents and costs. The whole-property rent reduction applies across collected room rent while fixed bills remain unchanged.

Explore the other calculators

BTL profit after tax Estimate UK buy-to-let cash flow after running costs, mortgage payments and tax. Compare rental yield, upfront cash and cash-on-cash ROI.HMO profit & ROI Calculate HMO cash flow and ROI using individual room rents, voids, bills, licensing allowances, finance and estimated tax. Free UK planning tool.Section 24 Estimate rental cash after income tax and residential finance-cost relief. See why taxable property profit can differ from spendable buy-to-let cash.Limited company vs personal Estimate company buy-to-let cash after corporation tax and compare personal ownership on matching inputs. Company figures exclude personal extraction tax.
ASSUMPTIONS & SOURCES

How the calculations work

Enter your property, finance, running costs and tax details in the four stages. Choose a single-household letting or an HMO with separate rents for each room, then compare cash purchases, interest-only borrowing and repayment mortgages.

Rental yield: gross yield is scheduled annual rent divided by purchase price. Net yield deducts empty periods and running costs before dividing by purchase price; both are before finance and tax.

Cash profit and ROI: pre-tax cash deducts running costs and mortgage payments from collected rent. Post-tax cash also deducts estimated income or corporation tax. Cash-on-cash ROI divides annual cash profit by all upfront cash, including purchase costs and your opening reserve. Choose Pre-Tax or Post-Tax in the ROI box; the assessment translates pre-tax cash ROI into annual pounds per £1,000 invested, while the score uses post-tax ROI. Capital repayments and property price growth are not cash profit; company figures are before personal extraction tax.

Cash recovery: payback is when cumulative post-tax rental cash covers the upfront investment. Optional rent and cost growth start in year two. The projection holds tax rules and other income constant, and excludes a property sale or capital appreciation. The stress tests explore lower rents and, where relevant, higher mortgage rates; they are not lender affordability decisions.

Tax rules checked 9 September 2026; HMO guidance checked 10 September 2026. Operating figures use 2026–27 tax rules for a full 12 months, not a forecast of future tax years. No automated market data or AI provider is connected.

All non-tax example figures are editable planning estimates as at this date. Your price, rent and financing are illustrative until replaced. Net yield uses purchase price as its denominator and deducts all annual cash running costs. Assessment weights are design choices, not industry benchmarks.

England · HMO licensingWales · HMO licensingScotland · HMO licensingNorthern Ireland · HMO licensingHMRC · SDLT ratesWelsh Revenue Authority · LTT bandsRevenue Scotland · LBTT bandsRevenue Scotland · 8% ADSHMRC · 2026–27 income-tax bandsHMRC · Landlord finance-cost reliefHMRC · Allowable rental costsHMRC · Corporation-tax ratesHMRC · Corporation-tax marginal reliefHMRC · Company purchase-tax relief