TaxKey
TaxKey: A focused UK Self Assessment tool for complex investment tax calculations. Ranked #104 of 123 in Personal Tax Software by our editors (3.0/10); pricing: Paid; best for UK investors with complex capital gains.
At a glance
- Editor score3.0 / 10
- PricingPaid
- Best forUK investors with complex capital gains
- Free planNo
- Facts checked22 Sep 2026
Where it wins
- Imports transactions from any broker and standardises CSV data
- Handles share-pooling, 30-day rules, foreign assets and RSUs
- Prepares auditable returns for review and HMRC submission
Where it doesn't
- Focused on investment-heavy UK Self Assessment workflows
- Paid product with no free plan
- Support is provided through email
Our verdict on TaxKey
TaxKey is UK tax reporting software for investors and high earners with investment-heavy Self Assessment needs. It imports broker and trading-platform transactions, calculates capital gains and investment income, and supports foreign shares, dividends, RSUs and tapered pension allowance calculations. The product also prepares Self Assessment returns for review and submission to HMRC. It is aimed at individuals, accountants and organisations handling UK investment tax reporting rather than broad personal-tax workflows.
Its strongest area is the depth of its investment calculations. TaxKey supports UK share-pooling, 30-day-rule and bed-and-breakfast calculations, alongside automated CSV ingestion and transaction standardisation. Foreign-asset and RSU support adds coverage for more complex portfolios, while auditable gain and loss calculations provide a review trail. The Individual Self Assessment plan includes broker imports, automatic capital gains and investment-income calculations, tapered pension allowance support and an HMRC-compliant return ready for submission. TaxKey states that it does not provide personalised tax advice.
The paid plan structure extends beyond individual filing. Accountant Pro adds multi-client portfolio and tax reporting, bulk data imports, collaboration tools, advanced compliance reporting, priority support and account management. White Label & API provides access to UK investment tax calculations, plus white-label or co-branded interface options and zero-knowledge hosting options. The product runs in the cloud through web and API access, with email support. TaxKey is a strong fit for UK investors with complex capital gains or professionals managing multiple investment-tax clients; people seeking a general personal-tax tool should choose a broader alternative.
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TaxKey pricing
All 3 TaxKey plans and prices →
TaxKey fact sheet
| Free plan | No |
|---|---|
| Paid from | Not verified |
| Self-employment support | Not verified |
| Investment income | Yes |
| Rental income | Not verified |
| State filing | Not verified |
| Mobile access | Not verified |
| Audit support | Not verified |
| Deployment | Cloud |
| Platforms | Web |
| Support | |
| Built for | Solo, Small business, Mid-market, Enterprise (editorial estimate) |
| Pricing | Paid (source) |
| Website | taxkey.co.uk |
| Facts checked | 22 Sep 2026 |
Alternatives to TaxKey
- TurboTaxA broad US tax filing suite with free simple returns and paid expert support.9.3
- H&R Block OnlineA flexible tax-filing service with free simple returns and guided expert help.9.0
- TaxActA broad US tax filing option with free entry, paid coverage, and expert help.8.8
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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