In brief
- Model full completion stack at £400,000.
- Compare nearby brackets before final offer.
- Use real fee quotes early.
- Keep a contingency reserve.
Definition in plain English
A £400,000 moving-home purchase is a common decision bracket where tax, legal and lender assumptions must be aligned early.
Context
Use this guide to build a realistic completion budget around £400,000 and avoid late-stage affordability surprises.
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)
Why £400,000 deserves scenario testing
Mid-range purchases can still be highly sensitive to fee assumptions and buyer status.
A small price change can shift total completion cash more than expected.
Scenario planning improves offer discipline and negotiation confidence.
Suggested planning method
Run £375,000, £400,000 and £425,000 with identical assumptions.
Test first-time and additional-property alternatives where relevant.
Use outputs to set a ceiling that protects your contingency.
Before-exchange checks
Confirm legal, survey and lender assumptions from live quotes.
Re-run numbers after material negotiation changes.
Ensure final legal statement aligns with your latest model.
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.
Frequently asked questions
Is £400,000 still a threshold-sensitive price point?
Yes. Nearby price movement can still change total completion cash materially.
Should I include non-tax costs every time?
Yes. Full-cost modelling is more reliable than tax-only planning.
How many scenarios are enough?
At least three: lower, base and higher price cases.
Do city pages change tax rules?
No. They support local-intent planning, but nation-level tax rules apply.
What confirms final numbers?
Your conveyancer’s final completion figures and official guidance.
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.