Can I file company tax myself? (Realistic guide for UK directors).

When you can realistically file yourself

You are a strong candidate for self-filing if:

• You are a micro-entity
• One company
• No group
• No overseas activity
• Straightforward income and expenses

This describes thousands of UK directors.

When you should probably use an accountant

• Complex group structures
• International tax
• Significant R&D claims
• Complex share issues
• Capital gains events
• You genuinely don't understand your numbers

There's no shame in using one. The key is using one when necessary — not automatically.

Why directors assume they can't self-file

Because terminology sounds technical, HMRC documentation is dense, and the name “CT600” feels intimidating. But structurally, for simple micro-entities, the flow is manageable.

What you need to self-file

1. Accounting period dates
2. Income and expenses
3. Clear summary of profit
4. Ability to generate correct structured outputs
5. Digital submission

The risk question

The real question isn't “can I?” It's: Is my company simple enough? If yes — self-filing is realistic.

Common misconceptions

• “You always need an accountant.” Not true. Many micro-entity directors file successfully without one.
• “It's too technical for non-accountants.” The terminology can be intimidating, but the underlying process for simple companies is straightforward. What matters is good tooling that guides you through the steps.
• “If I make a mistake, HMRC will fine me immediately.” HMRC generally gives you the chance to correct errors. The bigger risk is not filing at all, or filing late.

What does self-filing actually involve?

For a micro-entity, the typical self-filing process:

1. Gathering your numbers — income, expenses, and balance sheet items you already know.
2. Preparing accounts — in the format expected for micro-entities (FRS 105 style).
3. Preparing a corporation tax return — the CT600, based on your accounts.
4. Submitting digitally — accounts to Companies House, CT600 to HMRC.
5. Paying any tax due — if your company made a profit.

Each of these steps is manageable if your company is simple.

When to seek professional help

Even if you start self-filing, there are moments where professional advice is sensible:

• Your company is approaching the upper limits of micro-entity thresholds
• You're claiming reliefs you don't fully understand
• There's been a significant change in your company's structure
• You're unsure about capital allowances or depreciation adjustments

In those cases, a one-off consultation can be more cost-effective than a full annual retainer.

Summary

If your company is genuinely simple, you may not need to pay hundreds in accountant fees for routine filing. Start here: File company accounts & CT600 online · How to file company tax in the UK · See pricing.