Many company directors assume that being a director automatically means filing a Self Assessment tax return. Since 2018 that is no longer strictly true — HMRC removed the blanket requirement. But in practice most owner-directors do need to file, because they take dividends or have other untaxed income. This guide explains exactly when you must register, the deadlines, and what happens if you miss them.
Self Assessment Key Dates 2026
- Register by 5 October after the tax year you first need to file
- Online filing deadline: 31 January following the tax year end
- Paper filing deadline: 31 October
- Tax payment due: 31 January (plus payments on account if over £1,000)
- Dividend trigger: generally file if dividends exceed £500 and tax is due
- Late filing penalty: £100 immediately, rising after 3 months
Do you need to file as a director?
You must register for Self Assessment if any of the following apply: you received dividends above the £500 allowance on which tax is due; you have untaxed income (rental, foreign, self-employment, savings interest over the allowance); your total income exceeds £100,000; you owe the High Income Child Benefit Charge; or HMRC has specifically asked you to file.
If your only income is a salary already taxed under PAYE and you take no dividends, you may not need to file at all. Most owner-directors, however, take a small salary plus dividends — which means a return is required.
How to register
Register online through your Government Gateway account. HMRC issues a Unique Taxpayer Reference (UTR) by post, which can take up to two weeks, so don't leave it late. The deadline to register is 5 October following the end of the tax year (which runs 6 April to 5 April) in which you first had a filing obligation.
Once registered you file every year until you tell HMRC you no longer need to — for example if you stop taking dividends.
What to report
On the return you declare your salary and PAYE tax (from your P60), dividends received, and any other income. If you run a small salary plus dividends, this is where your personal tax on dividends above £500 is calculated at 8.75%, 33.75% or 39.35% depending on your band — see our salary vs dividends guide.
Keep your dividend vouchers and P60 to hand. Non-resident directors have a separate residence section and may rely on a double tax treaty — see our non-resident director PAYE guide.
Paying your tax and payments on account
Tax owed for the year is due by 31 January. If your Self Assessment bill exceeds £1,000, HMRC also asks for payments on account — two advance instalments toward next year's bill, due 31 January and 31 July, each 50% of the current year's tax. This often surprises first-time filers, so budget for it.
Deadlines and penalties
Miss the 31 January online deadline and you get an automatic £100 penalty, even if you owe no tax. After three months, daily penalties of £10 (up to £900) apply; after six and twelve months, further percentage-based penalties are added, plus interest on unpaid tax. Filing and paying on time is far cheaper than any excuse.
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View company packagesFAQ
Do all company directors have to file a Self Assessment return?
No. Since 2018, being a director is not itself a reason to file. You must file if you have untaxed income, dividends above £500 on which tax is due, income over £100,000, or HMRC asks you to. Directors whose only income is PAYE salary with no dividends may not need to file.
When is the Self Assessment deadline?
Register by 5 October following the tax year. File online by 31 January (or on paper by 31 October) following the 5 April year end. Tax owed is due by 31 January, with payments on account on 31 January and 31 July if your bill exceeds £1,000.
How are dividends taxed on Self Assessment?
The first £500 of dividends is tax-free. Above that, dividends are taxed at 8.75% (basic), 33.75% (higher) or 39.35% (additional rate), depending on where they fall on top of your other income. You declare them on the dividends section of the return.
What are payments on account?
Advance payments toward your next year's tax bill, required if your Self Assessment liability exceeds £1,000. You pay two instalments — 31 January and 31 July — each equal to 50% of the current year's tax, then reconcile the following January.
What is the penalty for filing Self Assessment late?
An automatic £100 penalty applies the moment you miss the 31 January deadline, even with no tax due. After three months, £10 daily penalties (up to £900) accrue, followed by further penalties at six and twelve months plus interest on unpaid tax.