5. Full Cost Breakdown
Underestimating costs is one of the primary reasons buy-to-let underperforms. This module is the detailed reference behind the totals in Modules 2 and 4 — split into one-off purchase costs and recurring annual costs.
5.1 Stamp Duty (including the surcharge)
A buy-to-let is an additional property, so on top of standard Stamp Duty Land Tax you pay a surcharge. In England and Northern Ireland that surcharge is 5% (raised from 3% on 31 October 2024) and it applies to every band on any purchase above £40,000 — not just the top slice.
| Portion of price | Standard rate | Additional-property rate (England/NI) |
|---|---|---|
| Up to £125,000 | 0% | 5% |
| £125,001 – £250,000 | 2% | 7% |
| £250,001 – £925,000 | 5% | 10% |
| £925,001 – £1,500,000 | 10% | 15% |
| Over £1,500,000 | 12% | 17% |
On the £250,000 example used throughout this course, that's £15,000 (standard £2,500 + 5% surcharge £12,500). This is a non-recoverable capital cost that goes straight onto your total return calculation.
Scotland and Wales differ. Scotland's Additional Dwelling Supplement (LBTT) is 8% (since December 2024); Wales's higher LTT rates for additional property start at 5%. Always run the exact figure through a calculator for the correct nation before you offer.
5.2 One-off purchase costs
Beyond the deposit and SDLT, budget for the transaction costs below. Ranges are typical and vary by property, lender and area.
| Cost | Typical range | Notes |
|---|---|---|
| Conveyancing / legal | £1,000 – £2,000 | Higher for leasehold or complex title |
| Survey | £400 – £1,500 | Level 2 homebuyer to full Level 3 building survey |
| Mortgage arrangement fee | £1,000 – £2,000 | Sometimes a % of the loan; can be added to the balance |
| Broker fee | £0 – £500 | Some are lender-paid |
| Initial safety certificates | £250 – £500 | EICR, gas safety, alarms — see 5.4 |
| Furnishing (if let furnished) | £2,000 – £6,000 | Optional; depends on tenant market |
Cutting corners on the survey or legal work to save a few hundred pounds is a false economy — these are the checks that catch the problems that cost tens of thousands later.
5.3 Recurring annual costs
These repeat every year and must be treated as non-negotiable expenses, not optional deductions. The percentages below are the assumptions used in the Module 4 cashflow.
| Cost | Typical amount | Notes |
|---|---|---|
| Letting agent — full management | 10–15% of rent + VAT | Tenant-find only is cheaper but you self-manage |
| Maintenance & repairs | ~10% of rent, or ~1% of value/yr | Costs cluster — budget annually, spend irregularly |
| Landlord insurance | £150 – £400/yr | Buildings + landlord liability; rent protection optional |
| Gas safety certificate (CP12) | £60 – £90/yr | Annual, legally required where gas is present |
| EICR (electrical) | ~£40 – £60/yr | £150–£300 every 5 years, amortised |
| Accountant | £150 – £300/yr | Higher for company ownership |
| Void allowance | ~8% of rent | Roughly one month vacant per year |
| Mortgage interest | Your largest cost | See Modules 3 and 4 |
5.4 Compliance is a cost, not an option
Safety compliance is legally required and non-negotiable: a valid gas safety certificate (annual), an EICR (electrical, every five years), working smoke and CO alarms, and a minimum EPC rating. Energy-efficiency rules in particular are tightening — factor potential upgrade costs into older properties (this links to Modules 10 and 12).
5.5 The unexpected-costs buffer
Emergency repairs, regulatory changes and legal disputes don't appear on a purchase spreadsheet, but they arrive eventually. A buffer isn't pessimism — it's risk pricing. The investor who has budgeted for the boiler failing in January makes calm decisions; the one who hasn't makes forced ones.
Core principle: Buy-to-let succeeds when deals survive bad scenarios — not when they look good in perfect ones.
Educational information only. This does not constitute financial, tax or legal advice. The SDLT rates shown are current as of July 2026 for England/NI; other figures are typical ranges that vary. Tax and compliance rules change — verify against current HMRC, Revenue Scotland or Welsh Revenue Authority guidance, or with a qualified professional, before acting.