Self Assessment for Web Designers with a Limited Company: What You Need to Do (and When)

If you’re a web designer trading through a limited company, it’s easy to assume “the company pays tax, so I don’t need Self Assessment”. In practice, many directors do need to file a personal Self Assessment tax return as well — and HMRC expect it to be done accurately and on time.

This guide explains, in plain English, what Self Assessment means for limited company web designers, what you’ll usually need to report, and the deadlines to keep in mind.

Do limited company web designers need to do Self Assessment?

Your limited company is a separate legal entity. It pays its own tax (usually Corporation Tax) and files its own returns. But you may still need to file a personal Self Assessment tax return if you receive certain types of income.

As a director-shareholder, you’ll commonly need Self Assessment if you take:

• Dividends from your company
• Income not fully covered by PAYE (for example, if you have a small salary but dividends take you over certain thresholds)
• Benefits in kind (such as private medical insurance paid by the company)
• Other untaxed income (freelance work outside the company, rental income, side projects, crypto gains, etc.)

Even if you don’t strictly need to file, HMRC may have already issued you a notice to file a return. If they have, you must submit one — or formally ask HMRC to withdraw it. Ignoring it can lead to penalties.

Self Assessment vs Corporation Tax: what’s the difference?

It helps to separate the two:

• Corporation Tax is paid by the company on its profits. The company files a Company Tax Return (CT600) and statutory accounts.
• Self Assessment is your personal tax return. It reports your personal income (salary, dividends, and anything else), and works out whether you personally owe tax.

So, as a limited company web designer, you’re often dealing with both company compliance and personal compliance.

What you’ll typically include on your Self Assessment as a web designer director

1) Salary from your limited company

If you pay yourself a salary through payroll, it will be taxed via PAYE (if it’s above the relevant thresholds). Even so, the salary still appears on your Self Assessment return.

What you’ll need: your P60 (and P11D if there are benefits).

2) Dividends

Dividends are a common way limited company owners take income. They’re taxed differently from salary, and the tax depends on your total income for the year.

What you’ll need: dividend vouchers and a clear record of dividend dates and amounts. Dividends must be properly declared and supported by company records — they’re not just “transfers from the business account”.

3) Benefits in kind (if applicable)

If your company pays for something that’s personally enjoyed (for example, private medical insurance), that can create a taxable benefit.

What you’ll need: P11D details (or confirmation the benefit has been payrolled).

4) Other income (side work, rent, investments)

Many web designers have extra income streams: a small freelance job outside the company, template sales, affiliate income, YouTube revenue, or rental income. These often need to be included.

Be especially careful if you’re mixing personal and company activity. Income belongs either to you personally or to the company — and it needs to be treated correctly in the accounts and tax.

Key Self Assessment deadlines (UK)

For the tax year ending 5 April:

• 31 October: deadline for paper tax returns (rare nowadays)
• 31 January: deadline for online tax returns
• 31 January: deadline to pay any tax owed for that tax year

If you need to make Payments on Account (advance payments towards next year’s tax bill), those are usually due:

• 31 January (first payment)
• 31 July (second payment)

Missing deadlines can lead to automatic penalties, even if you don’t owe much tax. HMRC are not flexible simply because you were busy with client deadlines.

Common Self Assessment mistakes for limited company web designers

Confusing company income with personal income

If a client pays your limited company, that’s company income — not personal. Your personal tax return should reflect what you took out (salary/dividends), not the company’s turnover.

Taking “dividends” when there aren’t enough profits

Dividends can only be paid from available profits. If you take money out when the company can’t support it, it may be treated as a director’s loan — which can create extra tax issues.

Forgetting about student loan or High Income Child Benefit Charge

These can catch people out, especially where dividends push income over thresholds. A return can be technically correct but still result in an unexpected bill if these apply.

Leaving it too late to plan for the tax bill

Dividends aren’t taxed at the point you take them — the bill often comes later. It’s sensible to set money aside as you go, so January doesn’t become a nasty surprise.

What good record-keeping looks like (in real life)

If you want Self Assessment to be straightforward, aim for:

• A clear split between business and personal bank accounts
• Proper payroll records for salary
• Dividend paperwork (vouchers) and a simple dividend log
• Up-to-date bookkeeping so you know what profits are available

This is also where good software and processes help. When your books are tidy, your tax return is usually calmer, quicker, and less likely to trigger HMRC questions.

How Tax Digital can help

At Tax Digital, we support limited company owners who want things done properly without the stress. If you’re a web designer running a limited company, we can help you:

• work out whether you need Self Assessment
• prepare and file your personal tax return accurately
• plan your salary and dividends sensibly
• stay on top of deadlines and avoid preventable penalties

If you’d like help getting your Self Assessment sorted, or you’re not sure what you should be reporting, we’re happy to talk it through.