Buy-to-let (BTL) is the most common entry point into property investment: you buy a property, let it to a tenant on an assured shorthold tenancy, and hold it for monthly rental income plus long-term capital growth. It is conceptually simple, but doing it properly means following a disciplined process from the very first decision to the eventual sale. Here is that process, step by step, with nothing skipped.
Step 1 — Define your strategy and goals
Before looking at a single property, decide what you actually want. Are you investing for monthly cashflow, for capital growth, or a balance of both? This determines everything — the areas you target, the property type, and the yield you need. High-yield areas (often the North of England) prioritise cashflow; high-growth areas (often the South) prioritise appreciation. Write down a target: for example, "6%+ gross yield and at least £200/month net cashflow after all costs".
Step 2 — Arrange your finance in principle
Speak to a buy-to-let mortgage broker before you offer on anything. BTL mortgages are assessed differently to residential ones: lenders use the expected rent (via a stress-tested Interest Coverage Ratio, typically 125%–145% of the mortgage payment at a stressed rate), not just your salary. Most BTL lending is interest-only, with a typical deposit of 25%. Get a Decision in Principle so you know your realistic budget and can offer with credibility.
- Deposit: typically 25% of the purchase price (some products need 20% or 40%).
- Product fees: arrangement fees can be 1%–2% of the loan or a flat fee — factor them in.
- Stress test: the rent must usually cover 125%–145% of the interest at a stressed rate (often 5.5%+).
- Consider whether to buy personally or through a limited company — see Should you buy through a company?.
Step 3 — Choose the right area
Research areas against your goal, not just gut feel. Look at average yields, tenant demand (void risk), average sold prices and rental prices, transport links, employers, universities, and regeneration plans. A strong BTL area has consistent tenant demand, a healthy yield, and a reason to believe values will hold or grow. Verify demand with real rental listings and local letting agents, not assumptions.
Step 4 — Source and appraise deals
Find properties through portals, local agents, auctions and sourcing agents. For each candidate, run the full numbers: purchase price, deposit, mortgage payment, all running costs (management, maintenance, insurance, void allowance, ground rent/service charge if leasehold), and the resulting net cashflow, gross yield and return on capital. Only proceed with deals that hit your pre-set targets — never fall in love with a property that does not stack up.
Run the numbers properly
A deal that looks fine on gross yield can be loss-making once Section 24 tax, voids and maintenance are included. Model net cashflow after everything, and stress test it at a higher interest rate before you commit.
To make this concrete, here is a realistic single-let deal in a typical northern high-yield area. Notice how the headline gross yield of 8% is genuinely strong, but the number that actually pays you is the net cashflow after every cost — including the mortgage and a void/maintenance allowance.
Worked example — £150,000 buy-to-let
Where every £1,000 of rent goes
Gross yield vs the yield that actually matters
Step 5 — Make an offer and go under offer
Offer based on the numbers and comparable evidence, not the asking price. Once accepted, you go "under offer" / "sold subject to contract". Instruct a solicitor (conveyancer) experienced in BTL, and formally apply for your mortgage so the lender can instruct a valuation.
Step 6 — Survey, valuation and legal due diligence
- Mortgage valuation: the lender confirms the property is worth the price and is lendable.
- Survey: commission at least a HomeBuyer (Level 2) survey, or a full Building Survey (Level 3) for older properties, to uncover defects.
- Conveyancing: your solicitor checks title, leasehold terms, searches (local authority, environmental, drainage), and any restrictions.
- Fix your finance: confirm the mortgage offer and lock the deposit and purchase funds.
Step 7 — Exchange and complete
At exchange of contracts you pay the deposit and the purchase becomes legally binding with a completion date set. At completion, the balance is transferred, you get the keys, and you legally own the property. Your solicitor handles Stamp Duty Land Tax (including the 3% additional-property surcharge for most investors) and registers you at the Land Registry. See the tax detail in the buy-to-let tax guide.
Step 8 — Prepare the property and stay compliant
Before a tenant moves in, the property must be safe and legally compliant. This is non-negotiable and skipping it can void insurance and expose you to prosecution.
- Gas Safety Certificate (CP12) — annual, from a Gas Safe engineer.
- Electrical Installation Condition Report (EICR) — at least every 5 years.
- Energy Performance Certificate (EPC) — minimum E rating required to let (rising standards expected).
- Smoke alarms on every floor and carbon monoxide alarms where required.
- Right to Rent checks, a compliant tenancy agreement, and protecting the deposit in a government-approved scheme within 30 days.
- Landlord insurance (buildings + liability, ideally rent guarantee).
Step 9 — Let the property and manage it
Advertise (self-manage or via a letting agent), reference the tenant, sign the tenancy, take the deposit and first month's rent, complete a detailed inventory with photos, and hand over. Ongoing, you either self-manage (handling rent collection, repairs, renewals and compliance yourself) or pay an agent typically 8%–12% of rent to do it. Keep meticulous records for tax and keep certificates current.
Step 10 — Review performance and plan the exit
Review the property annually: is the rent at market level, is the mortgage on the best rate (remortgage when the deal ends), and is it still meeting your goals? Over time you might refinance to release equity for the next purchase, or sell. On sale you pay Capital Gains Tax on the profit (reportable and payable within 60 days for UK residential property). A clear exit plan — sell, hold for income, or refinance and scale — is what turns one property into a portfolio.
Where buy-to-let investors lose money
- Chasing headline gross yield and ignoring net cashflow after Section 24, voids and maintenance — the deal above looks like 8% but pays like 5%.
- Forgetting the 3% Stamp Duty surcharge and buying costs, so the real cash needed is far more than the deposit alone.
- No void or maintenance reserve — one empty month plus a boiler replacement can wipe out a whole year of profit.
- Not stress-testing the mortgage: at 5.5% the deal works, but many landlords bought at 2% and were caught out on remortgage.
- Buying in your own name as a higher-rate taxpayer without checking whether a company would have been far more tax-efficient.
Where to go next
Once you are comfortable with single-let BTL, the natural progressions are higher-yield strategies like an HMO, capital-recycling via BRRR, or short-let income via serviced accommodation. Each builds on the fundamentals you have just learned.