HMRC letter codes · One-to-many letters
CompC1IDMMLetter about distribution or dividend income that may need declaring
Published by its source on 6 February 2024. A date in the letter that has passed stays passed: what a passed date means.
Last reviewed 14 October 2026 · How Tax Letters checks its facts
In short
HMRC's letter CompC1IDMM is headed “You may need to declare distribution or dividend income”.
“CompC1IDMM … You may need to declare distribution or dividend income”
CIOT: copy of HMRC letter CompC1IDMM, published on its page · checked 14 October 2026
Information, not advice: this page reports what HMRC, GOV.UK and the bodies named publish about CompC1IDMM. Each fact has its source and the day it was checked beside it.
When HMRC sends it
HMRC's letter CompC1IDMM says the accounts of a company showed a large drop in the profit and loss reserves, which normally means shareholders have received a distribution or dividend.
“CompC1IDMM … they showed a large drop in the profit and loss reserves for the accounting period ending … This normally means shareholders have received a distribution or dividend.”
CIOT: copy of HMRC letter CompC1IDMM, published on its page · checked 14 October 2026
CIOT said, on its page for HMRC's letter CompC1IDMM, that HMRC had started a One to Many letter campaign directed at taxpayers it suspected might need to declare income from distributions or dividends.
“HMRC have advised us that they have commenced a One to Many letter campaign directed at taxpayers who HMRC suspect may need to declare income from distributions or dividends.”
CIOT: HMRC One to Many letter – Inferred Distributions · checked 14 October 2026
What it asks
HMRC's letter CompC1IDMM asks the reader to check their Self Assessment returns to make sure they have declared any income from share distributions and dividends.
“CompC1IDMM … Please check your Self Assessment returns to make sure you’ve declared any income from share distributions and dividends.”
CIOT: copy of HMRC letter CompC1IDMM, published on its page · checked 14 October 2026
Time limits and rules
CIOT said that HMRC's letter CompC1IDMM gave the taxpayer 30 days to respond, and that if on reviewing their tax return they decided they needed to declare some income the letter directed them to HMRC’s GOV.UK guidance on making a disclosure.
“The letter provides 30 days for the taxpayer to respond. If on reviewing their tax return, they decide that they need to declare some income the letter directs them to HMRC’s GOV.UK guidance on making a disclosure.”
CIOT: HMRC One to Many letter – Inferred Distributions · checked 14 October 2026
Free help and HMRC contacts
HMRC's letter CompC1IDMM points to GOV.UK, search “Tell HMRC about underpaid tax from previous years”, for a reader who needs to declare income.
“CompC1IDMM … Go to GOV.UK search ‘Tell HMRC about underpaid tax from previous years’ and then follow the instructions.”
CIOT: copy of HMRC letter CompC1IDMM, published on its page · checked 14 October 2026
HMRC's letter CompC1IDMM gives the phone number 0300 123 0998 and an email address for a reader who has no income to declare.
“CompC1IDMM … If you have no income to declare … please call us on 0300 123 0998 or email us at [email protected]”
CIOT: copy of HMRC letter CompC1IDMM, published on its page · checked 14 October 2026
Free help first
These routes are described by GOV.UK, TaxAid and Citizens Advice themselves.
- HMRC's extra supportHMRC offers extra support if your health condition or personal circumstances make it difficult to contact HMRC, for example a mental health condition, financial hardship or being treated in hospital.
- Someone to deal with HMRC for youYou can authorise a friend, relative or voluntary organisation to talk to HMRC for you and help you fill in forms.
- TaxAidTaxAid helps people with tax problems who cannot pay for advice. Tax Help for Older People merged with TaxAid in July 2025.
- Citizens AdviceCitizens Advice gives confidential advice online, over the phone and in person, for free.
- CIOT: copy of HMRC letter CompC1IDMM, published on its page (checked 14 Oct 2026)
- CIOT: HMRC One to Many letter – Inferred Distributions (checked 14 Oct 2026)
- GOV.UK: Get help from HMRC if you need extra support (checked 7 Oct 2026)
- GOV.UK: Appoint someone to deal with HMRC on your behalf (checked 7 Oct 2026)
- TaxAid: About us (checked 8 Oct 2026)
- Citizens Advice: About us (checked 7 Oct 2026)