Buying your first flat is different from buying your first house, and the difference matters more than most guides admit. The price tag looks smaller, the deposit looks reachable, and the listing photos look good. But a flat purchase drags in a whole second layer of questions a house purchase does not: who owns the building, how long the lease has left, what the service charge will do next year, and whether the block has a cladding problem nobody has priced yet. Get those wrong and the cheap flat becomes the expensive one.
This guide walks through the whole process in order, with the flat-specific checks placed where they actually belong — before you offer, not after.
Start with the money, honestly
Before you browse a single listing, work out what you can actually borrow and what you can actually afford. Those are two different numbers, and lenders only care about the first.
A mortgage in principle, sometimes called an agreement in principle, is a lender's provisional statement of how much it would lend you, based on your income, outgoings, deposit and credit history. It is not a mortgage offer, and it can be withdrawn if your circumstances change or the property fails valuation. Get one early anyway: estate agents take you more seriously with one, and it stops you falling for flats priced above your reach.
Your deposit is the other constraint. For first-time buyers, 5% and 10% deposit mortgages exist, but the rates and product choice improve sharply at 10% and again at 15% and 20%. Saving the extra 5% can be worth more than buying six months sooner. Budget separately for buying costs on top of the deposit: conveyancing (roughly £800–£2,000 including disbursements for a straightforward flat), a survey (£400–£1,000 depending on level), mortgage arrangement and valuation fees (often a few hundred pounds, sometimes £0 on a product deal), and stamp duty (see below). A realistic first-time budget keeps £3,000–£5,000 aside for these on top of the deposit, more in London.
Affordability is not just the mortgage payment. For a flat, add the monthly service charge and any ground rent to the mortgage payment before deciding whether the flat is affordable. A £1,100 mortgage plus a £250 monthly service charge is a £1,350 monthly housing cost. Lenders do not always stress-test the service charge the way they should, so do it yourself.
The flat-specific checks that come before the offer
With a house, the building is yours and the land is yours. With a flat, you are almost always buying a leasehold interest in one unit inside a building someone else owns and manages. That single fact creates the checks that sink more flat purchases than anything else.
Lease length. A lease is a wasting asset: every year, it gets a year shorter. Below 80 years, extending the lease gets much more expensive because the freeholder can charge "marriage value" — a share of the increase in the flat's value created by the extension. As a rough rule, treat 85+ years as comfortable, 80–85 years as "price in an extension", and under 80 years as "do not proceed without specialist advice and a price that reflects the extension cost". Always ask for the exact remaining term in years, not a vague "long lease".
Ground rent. On newer leases, ground rent is typically a peppercorn (effectively £0) following the Leasehold Reform (Ground Rent) Act 2022, which applies to most new residential leases granted after 30 June 2022. On older leases, ground rent can be fixed, inflation-linked, or — the dangerous kind — doubling every 10 or 25 years. A doubling ground rent can make a flat unmortgageable with some lenders and should be treated as a red flag until a solicitor confirms otherwise.
Service charge and the managing agent. Ask for the last three years of service charge accounts, the current year's budget, and whether any major works are planned. A service charge that jumps from £1,200 to £3,000 a year is not a rounding error; it usually means a roof, lift or cladding bill is coming. Ask who manages the block, whether residents have a right-to-manage company, and how big the reserve (sinking) fund is. An empty reserve fund means the next big repair lands on leaseholders as a one-off bill.
Cladding and building safety. For flats in blocks of 18 metres or more (or seven storeys), ask whether an EWS1 form exists and what it says, and whether the building has a building assessment certificate. Leaseholder protections under the Building Safety Act 2022 are complex and depend on the building's height, the lease date, and who the freeholder is. If the block has known cladding or fire-safety defects, get specialist advice before offering — some flats in affected blocks are difficult or impossible to mortgage until remediation is complete.
Restrictions in the lease. Read the lease (or have your solicitor summarise it) for restrictions that affect your life: pets, subletting, running a business from home, flooring rules (many leases require carpet in bedrooms), and alterations. A lease that bans subletting matters if you might rent the flat out later; a lease that bans hard flooring matters if you hate carpet.
The buying process, step by step
1. Search and view. Filter by lease length and service charge, not just price. On viewings, look past the staging: check water pressure, phone signal, noise from neighbours and the street, the state of communal areas (they tell you how well the block is managed), and whether the windows are single or double glazed. Visit at a different time of day if you can — a quiet weekday flat can be a noisy Friday-night flat.
2. Offer. Offers on flats are usually made through the estate agent and are not legally binding in England and Wales until exchange of contracts. Offer on the basis of what you know: if the lease is short or the service charge is high, say so and price accordingly. Sellers of flats are often more flexible than the listing suggests, especially if the flat has been on the market for months.
3. Instruct a conveyancer. Use a solicitor or licensed conveyancer experienced with leasehold flats, not just houses. They will request the lease, the management pack (from the freeholder or managing agent — this can take weeks and cost £200–£500, usually paid by the buyer), and raise enquiries. The management pack is where leasehold deals stall, so instruct early and chase it.
4. Mortgage application and valuation. Your lender will value the flat (for its own purposes, not yours). A "down valuation" — the lender valuing below your offer — means you must cover the gap, renegotiate, or walk away. This is more common with flats than houses, especially new-builds and short leases.
5. Survey. A mortgage valuation is not a survey. For a flat, a Level 2 (HomeBuyer) survey is the usual choice; a Level 3 (building survey) makes sense for older conversions or flats with visible problems. The surveyor cannot inspect the whole block, but they can flag damp, roof issues, and lease-related risks worth a solicitor's follow-up.
6. Searches and enquiries. Your conveyancer runs local authority, drainage, environmental and other searches, and checks title, lease terms, and any restrictions. For flats, the replies from the managing agent (the "LPE1" form) matter as much as the searches: arrears, planned works, disputes, and insurance details all live there.
7. Exchange. Exchange of contracts is the point of no return: you pay the deposit (usually 10% of the price, though your solicitor may negotiate less) and you are legally committed. Check the completion date, the contents list, and that your buildings insurance is in place (for flats, the freeholder usually insures the building and recharges you through the service charge — confirm this rather than assuming it).
8. Completion. On completion day, the money moves, you get the keys, and the title is registered in your name. Your solicitor will register the lease transfer with the Land Registry and serve notice on the freeholder. Keep the completion statement and all lease documents — you will need them when you sell or extend.
Stamp duty for first-time buyers
Stamp Duty Land Tax (SDLT) is the tax on property purchases in England and Northern Ireland (Scotland has LBTT and Wales has LTT, with different rules and thresholds). Since April 2025, first-time buyer relief in England means no SDLT on the first £300,000 of a property priced up to £500,000, with 5% charged on the portion between £300,001 and £500,000. Above £500,000, first-time buyer relief does not apply at all and standard rates apply to the whole price. Standard residential rates since April 2025 start at 0% up to £125,000, then 2%, 5%, 10% and 12% bands above that.
Worked example: a first-time buyer purchasing a flat at £280,000 pays £0 SDLT under the relief. At £400,000, the bill is 5% of £100,000, which is £5,000. At £520,000, relief is lost entirely and standard rates apply, giving a bill of roughly £16,000. These thresholds are the April 2025 rules; confirm the current thresholds before exchange, because Budgets do change them, and the relief only applies if you have never owned property anywhere in the world and you will live in the flat as your main home.
New-build flats: the extra traps
New-build flats add three risks. First, the price: new-builds often carry a premium over comparable resales, which is why down valuations are common. Second, the timeline: developers often require exchange within 28 days of reservation, which pressures your conveyancer and lender. Third, snagging: inspect thoroughly before completion, list every defect in writing, and understand the developer's warranty (usually a 10-year structural warranty from a provider such as NHBC, with a 2-year developer defects period). Lease terms on new-builds should already be peppercorn ground rent, but check the service charge estimate against comparable resales — developer-set charges often rise sharply once residents take over management.
Mistakes first-time flat buyers keep making
Buying on price alone and discovering a £4,000 service charge. Skipping the survey because the flat "looks new". Assuming the lease is long because the agent said "long lease" without a number. Ignoring the management pack because it arrived late. And the biggest: falling in love with a flat before checking whether any lender will mortgage it. A flat that only cash buyers can buy is a flat you will struggle to sell.
Frequently asked questions
How much deposit do I need for a flat? Usually 5–10% as a first-time buyer, but 15–20% gives much better rates and more lender choice. A 5% deposit on a £250,000 flat is £12,500, but the monthly payment and rate will be higher than with a 10% deposit.
Is a 70-year lease too short? Yes, for most buyers. Below 80 years, extension costs jump because of marriage value, and some lenders refuse to lend at all. Either negotiate a big price reduction, get the seller to extend before purchase, or walk away.
Who pays for roof repairs in a block of flats? Usually all leaseholders, split by the apportionment in the lease, collected through the service charge (or a one-off demand if the reserve fund is empty). The freeholder arranges the work; you pay your share whether you wanted the work or not, subject to reasonableness and consultation rules.
Can I rent my flat out later? Only if the lease allows subletting, and usually only with the freeholder's consent and a buy-to-let mortgage. Check before you buy, not when you need to move.
Do I need a solicitor who specialises in leasehold? Strongly recommended. Leasehold conveyancing has failure modes (management packs, lease extensions, building safety) that general conveyancing does not, and an inexperienced conveyancer is a common cause of delays.
What is the single most important document? The lease itself, followed by the last three years of service charge accounts. Everything expensive about a flat lives in one of those two documents.
Related reading
- Buying a Flat vs a House in the UK: Pros, Cons and True Costs
- Leasehold vs Freehold Flats: What UK Buyers Must Know in 2026
- Service Charges on Flats Explained: What They Cover and How to Challenge Them
- Estate Agent Fees UK 2026: What You Will Actually Pay (With £ Examples)
