‘Self assessment’ is the system HMRC uses to collect income tax from individuals whose income is not fully taxed at source (i.e. those who are self-employed). For directors and shareholders of limited companies, the self assessment process is must be completed each year, typically by an accountant.
- Most directors and dividend‑receiving shareholders must file self assessment, even where the company is fully compliant for corporation tax.
- Non‑PAYE income such as dividends, directors’ loans, rental income, savings interest, capital gains and benefits in kind must be reported on the return.
- Register by 5 October using form SA1; penalties can apply for failing to register and file even if no tax is ultimately due.
- Key deadlines are 31 October for paper returns, 31 January for online filing and payment, and 31 July for the second payment on account.
- Once tax exceeds £1,000, payments on account and MTD‑driven digital reporting make planning, accurate records and professional advice increasingly important.
Who Needs to File a Self Assessment Return?
Most company directors must register for self assessment and submit a personal tax return each year. This applies even if the company itself is meeting its own tax obligations through corporation tax. The director’s personal tax position is assessed separately from the company’s.
Directors are not required to file if all of their income comes from a PAYE salary and no other sources of income exist. In reality, however, most directors receive a combination of salary and dividends, and dividends are not taxed through PAYE. This makes self assessment unavoidable for most owner-managed company directors. Shareholders who receive dividends above the dividend allowance have to file a self-assessment for regardless of whether they hold a director role. It is worth noting that this applies to shareholders too. Even someone who holds shares but plays no active role in the company still needs to file if they receive dividends above the allowance.
Income Sources That Trigger Self Assessment
The most common reason directors file is that they receive income outside of PAYE. This includes:
- Dividends from the company – taxed through self assessment, not payroll
- Directors’ loans – certain overdrawn loan account positions carry personal tax consequences
- Rental income – property held personally must be declared
- Savings interest – income above the personal savings allowance
- Capital gains – proceeds from disposing of assets such as shares or property
- Benefits in kind – company cars, private medical insurance, and similar perks
If a director receives a salary via PAYE, that portion is already taxed at source. The self assessment return captures everything else and reconciles the full picture. It is also how personal allowances and higher-rate tax adjustments are applied to the individual’s total income.
Registering for Self Assessment
The registration deadline for first-time filers is 5thOctober following the end of the tax year in which the new income arose. Directors register using form SA1, which is different from the form used by self-employed individuals. Once registered, HMRC issues a Unique Taxpayer Reference (UTR) number, which is used for all future correspondence. The HMRC self assessment registration page covers the process in full.
One thing that catches people out is the assumption that registration is only necessary when tax is owed. HMRC can issue penalties for failing to register and file even when the final liability turns out to be zero. The penalty and the tax bill are two entirely separate things.
Salary, Dividends and Your Self Assessment Position
In the interests of tax efficiency, most owner-managed limited companies pay directors a modest salary at or below the National Insurance threshold and extract further profits as dividends. Each income type is taxed differently and must be reported separately on the return. Understanding how salary and dividends interact, and the most tax-efficient way to structure them, is central to completing the self assessment return accurately.
Dividends are taxed at different rates from employment income. For 2025/26, basic rate taxpayers pay 8.75% on dividends above the allowance, higher rate taxpayers pay 33.75%, and additional rate taxpayers pay 39.35%. It is worth noting that these rates increase for 2026/27, with the basic rate rising to 10.75% and the higher rate to 35.75%. Using the wrong figures on a return, even accidentally, can trigger an HMRC enquiry. The dividend allowance has been cut significantly over recent years and currently stands at £500. Even modest dividend payments now create a self assessment liability where none would have existed a few years ago, when the allowance was as high as £5,000.
Directors’ Loans and Self Assessment
One area that frequently causes complications for directors is the director’s loan account. If a director withdraws more from the company than they have put in or earned through salary and dividends, the excess represents a loan from the company. An overdrawn director’s loan account that is not repaid within nine months of the company’s accounting year-end triggers a Section 455 tax charge on the company.
In addition to the company-level charge, the director may also face a personal benefit-in-kind tax if the loan is interest-free or below-market-rate, and this must be declared on the self assessment return. Correctly accounting for directors’ loans across both the company’s corporation tax return and the director’s personal return requires detailed record-keeping throughout the year. Your accountant should alert you to this situation and recommend the best course of action.
What Are the Key Self Assessment Deadlines?
Missing a self assessment deadline triggers automatic penalties. The dates are fixed each year and do not change.
| Deadline | Requirement |
|---|---|
|
5th October |
Register for self assessment (first-time filers) |
|
31st October |
Paper return submission deadline |
|
31st January |
Online return submission and tax payment deadline |
|
31st July |
Second payment on account (where applicable) |
For the 2025/26 tax year, the online filing and payment deadline is 31stJanuary 2027. The paper return deadline falls on 31stOctober 2026. Payments on account, advance payments towards the following year’s liability, may also be due in January and July for those whose tax bill exceeds a certain threshold.
Penalties for Late Filing and Payment
HMRC applies an automatic £100 penalty for any return filed after the 31st January deadline, even if no tax is owed. After three months, daily penalties of £10 begin to accumulate, up to a maximum of £900. Six and twelve-month penalties are applied on top for continued non-compliance.
Late payment of tax leads to both interest and surcharges. For directors with more complex tax returns, involving dividends, benefits in kind, and multiple income sources, the cumulative effect of these penalties can be quite substantial. The penalties are applied mechanically; HMRC does not consider whether the return was difficult or whether the director was unaware.
Completing the Return and Getting It Right
The self assessment return for a company director involves more moving parts than a standard employed person’s return. Employment income (from the company P60), dividend income, benefit-in-kind valuations, directors’ loan positions, and any additional income sources all need to be correctly reported.
Working with a qualified accountant means the return is filed accurately, available reliefs are not overlooked, and any HMRC correspondence can be handled from an informed position. The complexity of a director’s tax position reflects the responsibilities that come with a director’s legal obligations, and those responsibilities do not stop at the company’s accounts.
What Are HMRC ‘Payments on Account’?
Many directors are caught off guard by HMRC’s payments on account system. Once a self assessment tax bill exceeds £1,000, HMRC requires advance payments towards the following year’s liability. These are made in two instalments, the first on 31 January and the second on 31 July.
Each instalment equals 50% of the previous year’s tax bill. This means that in the first year a director’s tax liability exceeds the threshold, they must pay their current year’s tax plus a full year’s advance payment, all by 31 January. The cash flow impact can be significant if not anticipated. If the following year’s income is expected to be lower, a director can apply to reduce their payments on account. However, if the reduction is too aggressive and the actual liability turns out to be higher, HMRC will charge interest on the shortfall. Accurate income forecasting is therefore important, not just for planning purposes but for managing the payments on account position.
Making Tax Digital and Self Assessment
HMRC’s Making Tax Digital (MTD) programme is changing how self assessment is done for some individuals. From April 2026, MTD for Income Tax Self Assessment (MTD for ITSA) became mandatory for sole traders and landlords with qualifying income above £50,000.
Company directors whose only sources of income are salary and dividends from their limited company are not directly affected by MTD for ITSA. However, directors who also run a sole trade or hold rental properties alongside their directorial role may be within scope. The two activities are assessed separately, but both feed into the same self assessment return.
HMRC is moving towards real-time, digital reporting for all taxpayers. The self assessment system as it currently exists will continue to evolve as MTD expands to cover more taxpayers and income types. Directors who establish structured record-keeping systems now will be better placed as these requirements evolve.
Final Words
Self assessment is a non-negotiable part of being a limited company director. It captures income that falls outside PAYE, reconciles the personal tax position at the end of each year, and determines what, if anything, is owed. The deadlines are fixed, the penalties are automatic, and the scope for error is considerable. Approaching your self assessment with the same rigour applied to the company’s own filings is essential.
