HMRC Capital Gains Tax Letters: What Creatives Need to Know

Vicki P
Sep 3
3 min read

If you’ve already filed your 2024/25 self-assessment tax return, you might be in for an unwelcome surprise. HMRC is currently sending out letters to thousands of taxpayers, warning them that their Capital Gains Tax (CGT) may have been calculated incorrectly — even if they thought everything was spot on.

For self-employed creatives, this can feel like yet another admin headache. Maybe you sold some artwork, shares, or even a property, and you thought the numbers were sorted. But because of a mid-year change to CGT rates in October 2024, many returns have ended up with errors — sometimes underpaid, sometimes overpaid.

Here’s what’s going on, why HMRC is getting in touch, and what to do if you receive one of these letters.

Why HMRC Is Sending Capital Gains Tax Letters

The problem stems from a mid-year rate change that wasn’t always reflected in tax software or manually prepared returns. HMRC has spotted that lots of taxpayers may have reported CGT using the wrong rate, and it’s now asking people to double-check.

Put simply: if you sold something after 30 October 2024, you may not have applied the new higher rates. HMRC wants this corrected — quickly.

The October 2024 CGT Rate Changes Explained

Here’s what changed partway through the tax year:

Basic rate taxpayers: CGT on most assets (excluding residential property and carried interest) went up from 10% to 18%.
Higher and additional rate taxpayers: The rate increased from 20% to 24%.

Anything sold before 30 October 2024 stays on the old rates. Anything sold on or after that date should use the new ones.

The issue is that many returns didn’t account for this split. Some taxpayers applied the old rates across the entire year. Others tried to adjust but got the dates or calculations wrong.

Who Could Be Affected by the Miscalculations

HMRC is sending two types of letters right now:

“Your adjustment looks wrong”– You attempted to adjust for the new rate, but HMRC believes the calculation or disposal date doesn’t look right.
“No adjustment made”– You filed your return without reflecting the October change at all, meaning the old rates may have been applied across the year.

Even if you’ve already paid your bill, you might still hear from HMRC.

Why This Matters for Creatives

Capital Gains Tax isn’t just for City traders or property developers. Plenty of creatives get pulled into it when:

Selling artwork, film rights, or other intellectual property
Disposing of a second property
Selling shares in a production company or creative business

If those disposals happened around the October change, it’s easy to see how errors could slip through — especially if your tax software didn’t automatically

update.

What To Do If You Get a Letter

Don’t ignore the letter — but don’t panic either. You’ll normally have 30 days to respond. Here’s what to do:

Check HMRC’s CGT Adjustment Calculator Use the GOV.UK tool to work out the correct tax based on your disposal dates and income.
Compare with your return Look at what you originally submitted and see if the numbers match.
Amend if needed If you got it wrong, submit an amended return through your Government Gateway or tax software.
Confirm if correct Even if you did everything right, you still need to reply and let HMRC know.

The 30-Day Deadline: Why You Must Act Fast

The letter gives you 30 days to take action. Miss it, and you risk:

Penalties
Interest on underpaid CGT (backdated to when it should have been paid)
HMRC opening a full enquiry into your return

It’s far easier to deal with it straight away.

Missed the Deadline? What Happens Next

If you do miss the 30-day window, you can usually still amend your return. But interest will continue to build, and late penalties may apply.

If you’re not sure what to do — or you just can’t face another round of HMRC admin — it’s worth getting professional help.

How Creative & Numbers Can Support You

We know HMRC letters can be stressful, especially when you’d rather be focusing on your creative projects. That’s exactly why we’re here.

Our team can:

Review your CGT calculations and disposal dates
Confirm whether your return needs amending
Help you use HMRC’s online tools
Deal with HMRC on your behalf

We specialise in working with creatives, so we understand both the tax rules and the way your income streams work.