Estate Map vs HMRC Inheritance Tax Calculator: An Honest Comparison
HMRC offers an online inheritance tax checker at gov.uk. Estate Map offers a comprehensive IHT calculator covering every allowance, relief, and the upcoming 2026 and 2027 reforms. This guide explains what each tool actually covers, where each falls short, and which is right for your situation — without pulling any punches.
What HMRC Actually Provides
The HMRC inheritance tax pages on gov.uk include two online tools:
- The IHT threshold checker — answers the question "does this estate exceed the basic nil-rate band of £325,000?" You enter a rough estate total and it tells you whether the estate "may need to pay inheritance tax."
- The IHT return checker — helps executors determine whether they need to file an IHT400 return with HMRC.
Both tools serve an important purpose: they are clear, official, and authoritative. If your estate is straightforward — a single person, no business assets, no transferred allowances — the HMRC checker may tell you everything you need to know.
However, UK inheritance tax is rarely straightforward. Most estates involve at least one of: a surviving spouse, a property left to children, business assets, gifts made in the last seven years, or pension wealth. The HMRC checker does not model any of these.
Feature Comparison
| Feature | HMRC Checker | Estate Map |
|---|---|---|
| Basic IHT threshold check | ✓ | ✓ |
| Residence nil-rate band (RNRB) | ✗ | ✓ |
| Transferred NRB from deceased spouse | ✗ | ✓ |
| Transferred RNRB from deceased spouse | ✗ | ✓ |
| RNRB taper above £2M estate | ✗ | ✓ |
| Business Property Relief (BPR) | ✗ | ✓ |
| Agricultural Property Relief (APR) | ✗ | ✓ |
| Charitable donation relief (36% rate) | ✗ | ✓ |
| 7-year gift taper relief | ✗ | ✓ |
| April 2026 BPR/APR cap modelling | ✗ | ✓ |
| April 2027 pension inclusion | ✗ | ✓ |
| Scenario comparison (current vs reform) | ✗ | ✓ |
| Downloadable PDF report | ✗ | ✓ |
| Official HMRC-linked filing guidance | ✓ | ✗ |
| Free to use | ✓ | Free calculator / paid PDF |
Estate Map is an independent educational tool, not affiliated with HMRC. For official filing guidance, always refer to gov.uk.
When to Use HMRC's Tools
The HMRC tools are the right choice when you need:
- A quick eligibility check. If you want to know in under two minutes whether an estate is obviously below or above the basic threshold, the HMRC checker is fast and authoritative.
- Official confirmation before filing. The HMRC return checker tells you definitively whether you need to file an IHT400 — this is official guidance you can rely on.
- Very simple estates. A single person with modest savings and no property, business assets, or prior gifts may only need the basic check. If the gross estate is well below £325,000, there is nothing further to model.
When Estate Map Adds Value
Estate Map is designed for the majority of estates where the HMRC checker gives an incomplete picture:
- Married couples and civil partners. Unused nil-rate band and RNRB can be transferred from the first spouse to die, potentially doubling the tax-free allowance to £1,000,000. The HMRC checker does not model this.
- Homeowners leaving property to children. The residence nil-rate band adds up to £175,000 per person — but only if the home passes to direct descendants and only if the estate is below the £2M taper threshold. Estate Map calculates this precisely.
- Business owners and farmers. Business Property Relief (BPR) and Agricultural Property Relief (APR) can reduce or eliminate IHT on qualifying assets. The April 2026 changes cap 100% relief at £1 million. Estate Map models both the current rules and the reformed rules side by side.
- Anyone with pension wealth. From April 2027, unused defined contribution pension funds will be included in the taxable estate. For many people, this is the single biggest change to IHT planning in a generation. Estate Map shows the impact clearly.
- Those who have made gifts. The 7-year gift taper rule means gifts made in the last seven years may still count towards your estate — but at a reduced rate depending on when they were made. Estate Map tracks this.
Worked Example: The Henderson Estate
To illustrate the difference, consider what the HMRC checker and Estate Map would each tell the Henderson family.
The estate: Robert Henderson is a widower whose wife Patricia died in 2019, leaving everything to Robert. Robert's estate comprises:
- Main residence: £550,000 (to be left to their two adult children)
- Savings and investments: £350,000
- Shares in his trading company (unlisted): £400,000
- Personal possessions: £100,000
- Gross estate: £1,400,000
What the HMRC checker tells the family:
Gross estate £1,400,000 > £325,000 threshold → "This estate may need to pay inheritance tax. You may need to complete and send form IHT400."
This is technically correct but misleading. The family may believe a large IHT bill is unavoidable.
Scenario 1: Current rules (before April 2026)
- Gross estate: £1,400,000
- Business Property Relief (BPR) on company shares (100%): −£400,000
- Net estate after BPR: £1,000,000
- RNRB taper check: £1,000,000 < £2,000,000 → full RNRB applies
- Robert's NRB: £325,000 + transferred NRB from Patricia: £325,000
- Robert's RNRB: £175,000 + transferred RNRB from Patricia: £175,000
- Total allowances: £1,000,000
- Taxable estate: £1,000,000 − £1,000,000 = £0
- IHT: £0
Scenario 2: After April 2026 BPR cap
- BPR on company shares (£400,000): below £1M cap → 100% relief still applies
- All other figures unchanged
- IHT: £0 (no change in this case)
Scenario 3: After April 2027 (pension added)
Robert also has a £200,000 defined contribution pension pot. From April 2027, this enters the taxable estate.
- Gross estate: £1,400,000 + £200,000 pension = £1,600,000
- BPR on company shares: −£400,000
- Net estate: £1,200,000
- RNRB taper: £1,200,000 < £2,000,000 → full RNRB still applies
- Total allowances: £1,000,000
- Taxable estate: £1,200,000 − £1,000,000 = £200,000
- IHT at 40%: £80,000
The Henderson family would see a £0 IHT bill under current rules — but a £80,000 bill from April 2027 once the pension is included. This is not visible from the HMRC checker alone. Planning options exist now that may not be available once the rules change — taking professional advice before April 2027 is worth considering for estates with significant pension wealth.
What About Other Calculators?
Several other free IHT calculators exist online, typically from financial services firms, comparison sites, and accountancy practices. These vary considerably in quality. Common limitations include:
- Not modelling the RNRB taper for estates over £2M
- Missing the transferred allowance from a deceased spouse
- Not yet updated for the April 2026 BPR and APR changes
- No modelling of the April 2027 pension inclusion
- Single scenario only — no comparison of rules before and after reform
Estate Map was built specifically to model all three calculation scenarios side by side, making it easier to understand both your current position and the impact of the upcoming reforms on your estate. Read our complete IHT guide for 2026 for a broader overview of the rules.
Frequently Asked Questions
Does HMRC have an inheritance tax calculator?
HMRC provides an online inheritance tax checker at gov.uk that indicates whether an estate may exceed the threshold, and a separate tool to check if a return needs to be filed. These tools provide a basic eligibility check rather than a full calculation. They do not calculate your actual IHT liability, model multiple allowances, or account for reliefs such as BPR or APR.
Is the HMRC inheritance tax checker accurate?
The HMRC checker is accurate for its intended purpose — determining whether an estate is likely to exceed the basic nil-rate band threshold. However, it does not account for the residence nil-rate band, transferred allowances from a deceased spouse, business property relief, agricultural property relief, charitable donations, or the April 2026 and April 2027 reforms. Many estates that appear taxable on the HMRC checker will have no IHT liability at all once these allowances are applied.
Is Estate Map approved by HMRC?
Estate Map is an independent educational tool and is not affiliated with or approved by HMRC. It is designed to help families understand their potential IHT position using current HMRC rules and guidance. To actually file an inheritance tax return, you must use HMRC's official forms and processes — Estate Map does not replace this.
Can I use Estate Map instead of filing with HMRC?
No. Estate Map is an educational planning tool, not a tax filing service. If an estate owes inheritance tax, the legal personal representatives must file an IHT400 return with HMRC and pay any tax due within six months of the date of death. Estate Map's calculations can help you understand your position before engaging a solicitor or filing directly.
Why would I pay for Estate Map when HMRC's tools are free?
HMRC's free tools are useful for a basic threshold check, but they do not show your full IHT position. Estate Map models every relevant allowance and relief, shows the impact of the April 2026 BPR cap and April 2027 pension inclusion, and produces a professional PDF report you can share with a solicitor. If your estate is above £325,000 — which many are after including property — the additional clarity can be worth considerably more than the tool cost.
Should I use HMRC's tools or Estate Map?
Use HMRC's checker first to understand whether your estate is likely above the basic threshold. Then use Estate Map for a comprehensive calculation that accounts for all allowances, reliefs, and the upcoming reforms. The two tools serve different purposes and are complementary rather than competing.
See Your Full Inheritance Tax Picture
Estate Map calculates your IHT liability across three scenarios — current rules, April 2026 reforms, and April 2027 pension changes — with a professional PDF report.
Try the CalculatorThis article is for general information only and does not constitute financial, tax, or legal advice. Estate Map is not authorised or regulated by the Financial Conduct Authority. Inheritance tax rules are complex and individual circumstances vary significantly. Always consult a qualified solicitor, tax adviser, or financial planner before making estate planning decisions.