Guide

Capital Gains Tax Record Keeping 2026/27

Written by James Whitfield · Updated August 2026 Checked against 2026/27 HMRC rates

The paperwork you'll need to prove a CGT gain often dates back years before you sell - the purchase completion statement, the extension invoices, the broker contract notes. Lose them and the tax doesn't go away; you just find it harder to justify a lower gain, and HMRC can charge up to £3,000 for poor records on top.¹ Here's exactly what to keep, and for how long.

Key takeaways

Keep CGT records for at least 5 years after the 31 January filing deadline for the year you sold.¹
Shares and crypto use pooling, so you need the whole purchase history - not just the sale.
Export broker and exchange histories regularly - platforms close and older data disappears.
HMRC can charge up to £3,000 for failing to keep records, on top of any inaccuracy penalty.¹
Digital scans are fine - HMRC accepts faithful copies, no need to hoard the originals.

How long must you keep CGT records?

For individuals filing Self Assessment, CGT records must be kept for at least 5 years and 10 months after the end of the relevant tax year - roughly 6 years from the 31 January following the tax year. HMRC can open an enquiry up to 12 months after your return is filed, 4 years for incomplete disclosure, or 6 years where there is a loss of tax.

In practice, keep records for at least 6 years from the disposal date.

Worked example — retention clock for a 2026/27 disposal

Tax year of disposal ends	5 Apr 2027
Self Assessment filing deadline	31 Jan 2028
Keep records until at least	31 Jan 2033
Longer if you're still carrying losses from that year

That's five years past the 31 January filing deadline. If you claimed a loss in 2026/27 and only use it in, say, 2031/32, keep the supporting records until that later disposal is settled too.

Records to keep for property

For any property disposal - second home, buy-to-let, inherited or commercial - keep the following:

Original purchase contract / completion statement
Evidence of the purchase price paid (solicitor bill, bank statement showing funds transferred)
Stamp Duty Land Tax return and payment receipt
Solicitor and surveyor invoices on purchase
Receipts and invoices for all capital improvement works (not maintenance)
Sale contract / completion statement
Estate agent fee invoice and VAT receipt
Solicitor invoices on the sale
Probate valuation documents (for inherited property)

Keep digital copies and originals where possible. Solicitors and estate agents will usually provide duplicates if originals are lost.

Records to keep for shares and funds

Shares and unit trusts use the Section 104 pool, which means you must track the total cost of all shares of the same class in the same company across your entire holding period:

Broker contract notes for every purchase and sale
DRIP (dividend reinvestment plan) records - each reinvestment is a new purchase into the pool
Bonus issue records (shares received free from the company)
Rights issue records - details of new shares taken up and the cost paid
Stock split or consolidation notices
HMRC share scheme documents if shares were acquired through an employment scheme (SAYE, SIP, EMI, CSOP)
Annual broker statements showing your holding at year end

Most online brokers provide downloadable transaction histories going back many years. Download and save these regularly. Do not rely on the broker's platform staying accessible indefinitely.

Records for crypto assets

Crypto follows the same pooling rules as shares. Keep a record of:

Every purchase: date, amount of crypto, sterling cost at the time
Every disposal (sale, swap, spend or gift): date, amount disposed of, sterling value at the time
Mining, staking and airdrop receipts (separate income tax considerations also apply)
Exchange transaction histories in CSV format

Crypto exchanges can shut down or restrict access to older records. Export your transaction history regularly.

How to report and where records are needed

CGT disposals are reported in one of two ways, depending on the asset:

UK Residential Property Service - used for residential property disposals where CGT is due. Report within 60 days of completion. You will need all the property records listed above to complete this accurately.
Self Assessment - all other CGT disposals (shares, crypto, commercial property, business assets) are reported via Self Assessment by 31 January following the tax year end.

HMRC does not ask you to submit records with your return. But they must be available if HMRC opens an enquiry.

Penalties for not keeping records

HMRC can charge up to £3,000 for failure to keep records. That is on top of any penalty for an inaccurate return. If records are unavailable and you understate a gain, the accuracy penalty regime applies - from 30% to 100% of the unpaid tax depending on the nature of the error.

If records are genuinely lost - say in a fire or flood - notify HMRC promptly and provide your best estimate using reconstructed evidence: bank statements, Land Registry records, or market data.

Calculate your CGT before you report

Use your records to enter accurate figures and get a 2026/27 CGT estimate before filing with HMRC.

Open the CGT calculator

Frequently asked questions

How long do I keep CGT records?

HMRC requires records to be kept for at least 5 years and 10 months after the end of the tax year in which the disposal occurs - broadly 6 years. For example, for a disposal in the 2025/26 tax year (ending 5 April 2026), you should keep records until at least January 2032. If HMRC opens an enquiry the records must remain available throughout the enquiry period.

What happens if I lose my records?

If records are genuinely lost or destroyed, you should reconstruct the information as best you can from other sources: bank statements, Land Registry records (for property purchase price and date), broker statements, or correspondence. HMRC will generally accept reasonable estimates supported by available evidence. Inform HMRC if your records have been lost due to circumstances beyond your control. Penalties can apply if records are carelessly destroyed.

What records do I need for shares?

For shares you need contract notes for every purchase and sale, records of any dividend reinvestment plan (DRIP) purchases, bonus issues, rights issues, and stock splits. UK shares use a pooling calculation (the Section 104 pool), which means the entire purchase history of a particular share class must be available to calculate the allowable cost on disposal. Most brokers provide downloadable transaction histories - export and keep these regularly.

Can I store records digitally?

Yes. HMRC accepts digital records. Scanning paper documents and storing them securely in the cloud (for example in Google Drive, OneDrive or a dedicated accounting system) is acceptable. Ensure digital copies are legible, date-stamped where possible and backed up. HMRC does not require original paper documents as long as the digital copy is a faithful reproduction of the original.

I've lost the records for a house I bought 20 years ago - what now?

Reconstruct the base cost from what you can find. The Land Registry holds the purchase price and date for most properties bought since 2000, your old SDLT return or completion statement may be with the solicitor who acted, and conveyancers often keep files for years. For improvements, hunt out invoices, bank statements or even planning-permission records for an extension. HMRC will accept a reasonable, evidenced estimate - what it won't accept is a figure plucked from the air. Note down how you arrived at each number and keep the supporting scraps.

This page is for general information only and is not financial, tax or legal advice. Record-keeping requirements can vary depending on your specific circumstances. Consult a qualified accountant or tax adviser if you are unsure what records to keep.

Sources & references

The rates, allowances and rules in this guide are drawn from the official HMRC and GOV.UK sources below, checked for the 2026/27 tax year. Each link opens the relevant government page in a new tab.

Verified against published HMRC and GOV.UK guidance.