UTR and Self Assessment: A Trade Business Calendar
Check the filing requirement before registering
A Unique Taxpayer Reference identifies your tax record. It is not a trade qualification, scheme membership or permission to carry out gas or electrical work. Check HMRC’s filing criteria: sole-trader income of more than £1,000 before expenses is one reason a return may be required; other income and circumstances can also matter.
If HMRC has sent you a notice to file, follow that requirement or arrange the appropriate change with HMRC. Registration for Self Assessment, CIS and PAYE are separate decisions. Do not assume an employed person’s PAYE covers all private trade income.
Source: HMRC: who must send a return
A dated example: first-time 2025/26 filers
Fictional calendar, checked 2 October 2026. A new sole trader starts in June 2025, needs to file for 2025/26 and has not previously registered. HMRC’s registration deadline for that cohort is 5 October 2026. The usual paper-return deadline is 31 October 2026; the online-return deadline and balancing-payment date are 31 January 2027.
Those dates describe that tax year, not a rolling instruction to register “this week”. If you read this after a deadline, use HMRC’s current registration/filing route and resolve the missed step rather than waiting for another year. Newer starters must check the dates for their own tax year.
Sources: HMRC: September 2026 registration notice, HMRC: return deadlines
Find the right UTR and use the registration route
If you have previously been in Self Assessment, check your existing tax record before registering again. Your UTR is on HMRC correspondence and in your personal tax account. Use the official registration service for your situation, including restarting self-employment.
Keep the UTR in your private records. Share it only where needed for a legitimate tax/accountancy or CIS verification purpose. It does not belong on public job photographs, example worksheets or analytics events.
Copy your first-year calendar
- Tax year: ___; trading start date: ___; HMRC filing requirement checked: ___.
- Registration: applicable deadline: ___; submitted/date/reference: ___; existing UTR located: ___.
- Return: paper/online/MTD route: ___; deadline: ___; who prepares and who checks: ___.
- Payment: balancing amount/date from HMRC: ___; payments on account applicable: ___; dates/amounts: ___.
- Records: income invoices/payments: ___; expenses/receipts: ___; CIS statements: ___; missing items: ___.
- Next review: ___; unresolved HMRC/accountant question: ___.
Payments on account are separate advance payments, normally due 31 January and 31 July where applicable. HMRC explains exceptions, including a previous bill below £1,000 or enough tax paid outside Self Assessment. Use the actual bill, not a fixed percentage of each invoice as personal tax advice.
Source: HMRC: payments on account
Keep income, costs and CIS evidence distinct
Record business income, invoices, payments and expenses with supporting receipts. A CIS payment’s net bank amount is not the gross income figure; retain the payment/deduction statements. The CIS worked chain explains the separate contractor/subcontractor records.
HMRC normally requires self-employed records for at least five years after the 31 January submission deadline for the relevant tax year. Check longer-retention situations in the guidance. For MTD cohorts and cumulative updates use the MTD record-readiness guide.
Start the job paperwork with a quote record and the first-job pack. Tax filing stays with HMRC-compatible software or your authorised accountant.
Source: HMRC: self-employed records
Sources and references
Sol Wright
Sol is a co-founder of Tradehand, a UK trades marketplace More from Sol
