Explore More Capital Gains Tax Calculators
Capital Gains Tax Calculator
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CGT Relief Checker
Which relief might apply — PRR, BADR, Hold-Over
DIY vs Fixed-Fee Online Accountant vs Full-Service Accountant
| Option | Best for | What you get |
|---|---|---|
| DIY (HMRC's own services) | One simple disposal, confident filing yourself | You calculate and file directly via the CGT on UK property account or Self Assessment — free, but no second opinion |
| Fixed-fee online accountant | A few disposals, mixed asset types, want it filed correctly without a full engagement | Fixed, known-upfront price; they calculate and file the return; usually online-only with limited advisory scope |
| Full-service accountant | Multiple/complex disposals, business assets, ongoing tax planning | Advice on reliefs and timing as well as filing; typically your regular accountant, priced per engagement or on retainer |
What to check before choosing one
- Is CGT filing actually included, or is it an add-on to a general Self Assessment fee?
- Do they handle the 60-day property return specifically, not just the annual Self Assessment — some fixed-fee services only cover one or the other.
- Are they regulated — check for membership of a recognised body (ICAEW, ACCA, ATT, CIOT) via their public register, not just a claim on the accountant's own site.
- What happens if HMRC queries the return — is follow-up support included in the fee, or charged separately?
Typical fixed-fee online CGT filing services are priced per disposal or per return rather than as a percentage of the gain — always get the exact figure for your situation before instructing anyone, since ranges advertised publicly can be a starting "from" price rather than the full cost.
How this calculator works — Formulas & Method
Source: gov.uk/capital-gains-tax, ICAEW/ACCA/ATT/CIOT public registers · Decision logic, not a numeric formula
Constants used
| Constant | Value | Source |
|---|---|---|
| 60-day property return | Separate from annual Self Assessment | gov.uk/report-and-pay-your-capital-gains-tax |
| Self Assessment CGT deadline | 31 January following the tax year | gov.uk/self-assessment-tax-returns/deadlines |
| Recognised accountancy bodies | ICAEW, ACCA, ATT, CIOT | Each body's public member register |
Formulas
— Recommendation logic —
if disposals == one and confident → DIY via Self Assessment
else if disposals == many or (unsure and disposals != one) → full-service accountant
else → fixed-fee online accountant
if disposals == one and confident → DIY via Self Assessment
else if disposals == many or (unsure and disposals != one) → full-service accountant
else → fixed-fee online accountant
A simplified pointer based on 2 questions — actual choice should also weigh cost, whether business assets are involved, and your own comfort with HMRC filing. Always verify an accountant's regulation status directly on their professional body's register.
Get It Filed Correctly, Not Just Estimated
This calculator gives an estimate — actually reporting and paying it correctly is a separate step with its own deadline and paperwork.
- Mixed disposals in one tax year: a property sale on top of a share sale doesn't just add two bills together — the deadlines differ (60 days for property, 31 January Self Assessment for everything else) and the order gains are set against your allowance and rate bands changes what you owe. Getting the sequencing wrong is a common source of overpayment.
- Multiple disposals in one tax year: ordering and timing disposals across the 5/6 April boundary can materially change what you owe.
- Inherited or gifted assets: your acquisition cost for CGT purposes isn't always what you think — get the base cost confirmed.
- Business Asset Disposal Relief: can cut your rate to 18% on qualifying gains, but eligibility rules are strict.
A fixed-fee online accountant can handle the return and your wider Self Assessment together.
Compare Online Accountants →Transparency & Methodology
Methodology & Sources
Figures are public HMRC rates. For your exact position, use gov.uk/capital-gains-tax.
Not Tax or Legal Advice
Information only. Consult the Chartered Institute of Taxation or an adviser via the FCA Register.
Open Source
Formulas are public. Inspect on GitHub.
Frequently Asked Questions
Do I need an accountant to file Capital Gains Tax?
No — for a single straightforward disposal, HMRC's own CGT on UK property account or Self Assessment return lets you file directly. An accountant becomes more valuable as disposals multiply, asset types mix, or you're unsure about reliefs.
What's the difference between a fixed-fee online accountant and a full-service accountant?
A fixed-fee online accountant typically offers a known-upfront price for calculating and filing a specific return, often with limited advisory scope. A full-service accountant usually also advises on reliefs, timing and wider tax planning, priced per engagement or retainer.
How do I check if an online accountant is properly regulated?
Search the public member register of a recognised UK accountancy body — ICAEW, ACCA, ATT or CIOT — directly on that body's own website, rather than relying on a badge or claim shown on the accountant's own site.
Does a fixed-fee accountant handle the 60-day property CGT return?
Not always — some fixed-fee services cover only the annual Self Assessment return, not the separate 60-day UK property CGT return. Confirm this specifically before instructing anyone if you've sold property.