In brief
- Treat all-in completion cash as the core decision metric, not tax in isolation.
- Buyer type and nation can shift costs materially at the same property price.
- Run at least three scenarios before setting your offer ceiling.
- Confirm final treatment with official sources and your conveyancer.
Definition in plain English
Buying a house requires more cash than most first-time buyers expect. Beyond the deposit, you need cash to cover SDLT (stamp duty), legal fees, a survey, mortgage fees, and a contingency buffer. On a £300,000 purchase with a 10% deposit, total upfront cash typically runs to £38,000–£45,000 depending on your buyer type and fee choices. This guide breaks down every item.
Context
The deposit is the largest single item but rarely the only one. Buyers who focus solely on saving a 10% deposit and then discover SDLT and legal fees at the point of making an offer often need to delay. Planning from the total upfront cash requirement avoids this.
Use the calculator for this topic
Run multiple price points and buyer types before setting your final offer ceiling. Keep all assumptions visible in one place so comparisons stay honest.
Worked examples (home mover, typical fees)
The five cash pools every buyer needs
1. Deposit: the cash contribution toward the purchase price, with the balance funded by your mortgage. Minimum deposit is typically 5% (95% LTV), though 10% (90% LTV) gives access to better rates and 15–25% (75–85% LTV) gives access to the best products. On a £300,000 purchase, a 10% deposit is £30,000.
2. Stamp Duty Land Tax: the transaction tax due on completion. For a standard buyer at £300,000, SDLT is £5,000 (using post-April 2025 rates). A first-time buyer at £300,000 pays £0. An additional property buyer pays £20,000. The calculator on this site computes the exact figure for your combination of price, buyer type and nation.
3. Legal fees: your solicitor or conveyancer's costs including disbursements (searches, Land Registry, bank transfer fees). Total typically £1,200–£2,500 for a standard freehold purchase. Leasehold costs more.
4. Survey: a RICS HomeBuyer Report or Building Survey, commissioned independently of the lender's valuation. Cost typically £400–£800. Skipping this is a false economy — identifying defects before exchange gives you the option to renegotiate or withdraw.
5. Mortgage fees: arrangement fee (£0–£2,000, often added to the mortgage), booking fee (£100–£250), valuation fee (£150–£500). If you add the arrangement fee to the mortgage, it does not require upfront cash but adds to the debt.
Estimated total cash by purchase price
For a first-time buyer in England purchasing with a 10% deposit: at £250,000 — deposit £25,000, SDLT £0, legal £1,500, survey £500, mortgage fees £500, total approximately £27,500; at £350,000 — deposit £35,000, SDLT £2,500, legal £1,600, survey £550, mortgage fees £500, total approximately £40,150; at £450,000 — deposit £45,000, SDLT £7,500, legal £1,800, survey £600, mortgage fees £500, total approximately £55,400.
For a standard home-mover (not first-time buyer) in England purchasing with a 10% deposit: at £250,000 — deposit £25,000, SDLT £2,500, legal £1,500, survey £500, mortgage fees £500, total approximately £30,000; at £350,000 — deposit £35,000, SDLT £7,500, legal £1,600, survey £550, mortgage fees £500, total approximately £45,150; at £450,000 — deposit £45,000, SDLT £10,000, legal £1,800, survey £600, mortgage fees £500, total approximately £57,900.
These are estimates based on typical market rates. Use the calculator on this site for an accurate SDLT figure, then add your specific legal and mortgage fee quotes. Always maintain a contingency buffer of £2,000–£5,000 for unexpected costs — survey-identified repairs, mortgage re-applications after a down-valuation, or chain delays that require extending a mortgage offer.
What reduces cash requirements — and what to be cautious about
Gifted deposits from family reduce the cash you personally need to save, but lenders will require a signed gift letter confirming the money is not a loan. Gifted deposits above £10,000 may trigger additional anti-money laundering checks and your solicitor will need to trace the source of funds. Gifts are widely accepted and this process is routine — just plan for slightly more paperwork.
Adding mortgage fees to the loan reduces upfront cash but increases total borrowing. A £1,000 arrangement fee added to a 25-year mortgage at 4.5% costs approximately £700 in extra interest over the term. On a short-term fix (2–3 years), the interest cost is lower — around £150–£200. If cash is tight at completion, adding the fee to the loan is entirely reasonable.
Some government schemes such as Lifetime ISAs provide a 25% bonus on savings up to £4,000/year, effectively boosting your deposit by up to £1,000/year. First-time buyers using a LISA must ensure they understand the property price cap (currently £450,000) and the withdrawal penalty (25%, which effectively claws back the bonus plus 6.25% of your own savings) for non-qualifying purchases.
Decision framework used by careful buyers
Start with an offer ceiling based on total cash, not headline house price. In practice, buyers who only track deposit and mortgage payments can miss the transaction-cost layer, which is exactly where completions become stressful.
Use a three-pass approach: first estimate tax by nation and buyer type, then add realistic fees, then pressure-test the result by increasing the offer by £10,000 and £25,000. This shows how sensitive your budget is before bidding.
Treat the model as a planning instrument. Final legal liability always sits with official calculators and your conveyancer’s completion statement, but early visibility reduces avoidable surprises.
Practical checklist before making an offer
Confirm your likely buyer status first (home mover, first-time buyer, or additional property). Switching status can alter tax materially at the same price point, so this should be fixed before negotiating.
Collect at least two conveyancing quotes and check what is included. Buyers often compare legal fees without checking disbursements, search packages, leasehold supplements or transfer fees.
Keep a contingency buffer instead of budgeting to the exact minimum. A modest reserve can protect timelines when valuation, legal or lender admin costs move late in the process.
Cash requirement framework
Split planning into fixed minimums (deposit, tax, core legal costs) and variable items (survey scope, lender fee decisions, contingency).
Set a conservative cash floor before bidding and avoid stretching to a level that leaves no room for final-stage changes.
Use scenario modelling to decide whether a higher offer still fits your completion risk tolerance.
Frequently asked questions
How much cash do I need to buy a £250,000 house as a first-time buyer?
With a 10% deposit: £25,000 deposit, £0 SDLT (FTB relief), approximately £1,500 legal fees, £500 survey, £500 mortgage fees. Total approximately £27,500. With a 5% deposit: £12,500 deposit, same other costs — total approximately £15,000, though 95% LTV mortgages have higher rates. Add a £2,000–£3,000 contingency buffer.
What is the minimum deposit to buy a house in the UK?
Lenders require a minimum 5% deposit for most standard residential mortgages (95% LTV). Government mortgage guarantee schemes have enabled 95% LTV products for buyers with a 5% deposit. However, 10% deposits (90% LTV) give access to materially better rates, and 15–25% deposits unlock the most competitive products. A lower deposit means higher monthly payments and more interest paid over the term.
Do I need cash for stamp duty on top of my deposit?
Yes, unless your SDLT is £0 (e.g. first-time buyer below £300,000 in England). SDLT cannot usually be included in the mortgage — it must be paid from your own cash at completion. For a standard buyer at £300,000, SDLT is £5,000; at £400,000 it is £10,000. This is a significant cash requirement in addition to the deposit and should be planned for from the outset.
Can I include legal fees in my mortgage?
No. Legal fees are a completion cost paid from your own cash. Some lenders offer 'free legals' incentives where they pay your legal fees (up to a capped amount, typically £500–£1,000) as part of a remortgage product, but for purchase mortgages legal fees are paid by the buyer directly.
What is the recommended contingency buffer when buying a house?
Most solicitors and mortgage advisers recommend maintaining a £2,000–£5,000 contingency buffer above your calculated completion costs. This covers: survey-identified defects you choose to remediate; a mortgage application restarted after a down-valuation; estate agent re-marketing if a previous purchase falls through; or a chain delay requiring mortgage offer extension. Depleting reserves to exact minimum creates vulnerability.
How does a Lifetime ISA help with buying costs?
A Lifetime ISA (LISA) pays a 25% government bonus on savings up to £4,000 per year, giving a maximum £1,000/year bonus. On a purchase, the LISA must be used for a property costing £450,000 or less and you must be a first-time buyer. The LISA must be open for at least 12 months before you can use it. The 25% withdrawal penalty for non-qualifying uses (including properties above £450,000) effectively removes the bonus plus 6.25% of your own savings — plan the purchase price carefully.
What other costs should I budget for after buying?
Post-completion costs that catch buyers off-guard: removal costs (£400–£1,500 depending on distance and volume); buildings insurance (must be in place from exchange, not completion — typically £150–£400/year); Council Tax (often higher on a new property); utility connection fees; and any immediate renovation or decoration. These are outside the completion cost calculation but should be part of your overall budget plan.
References
- GOV.UK: Stamp Duty Land Tax — Primary SDLT rates and process guidance.
- Revenue Scotland: LBTT — Official LBTT rates and ADS information.
- Welsh Revenue Authority: LTT — Official LTT rates and higher-rate guidance.
For methodology and editorial policy, see Methodology and Editorial standards.