Business deadline guide

Corporation Tax guide for first-time UK company directors

Corporation Tax is the tax a limited company may pay on its profits. New directors often find it confusing because the tax payment deadline and the company tax return deadline are not necessarily the same date.

Written by the Business Sorted editorial team · Reviewed 18 July 2026

Last reviewed: 18 July 2026
Next review: Within 3 months, or sooner if official guidance changes.
Primary sources checked: Corporation Tax, Company Tax Returns, HMRC

Business Sorted is not HMRC, Companies House, an accountant or a legal adviser. Use this guide to understand the topic, then check the official source and get professional advice when your situation needs it.

Need to know in 30 seconds

The safest next step is to identify whether this applies to your business, check the official source and set a preparation reminder before the filing or payment date.

What it is

Corporation Tax is handled by HMRC and relates to company profits. The company normally needs accounting records to prepare figures correctly.

Who it applies to

This guide applies to UK limited companies. Sole traders usually deal with business profits through Self Assessment instead.

Why it matters

This topic matters because missed filings, unclear records or late payments can create avoidable admin, penalties, interest or extra support work. A simple reminder is useful only when it is tied to the correct official source.

When it applies

Corporation Tax applies when a company is active for tax purposes and has taxable profits or needs to report its position to HMRC.

Important deadlines

Tell HMRC when the company starts business activity.
Pay Corporation Tax by the relevant payment deadline for the accounting period.
File the Company Tax Return, usually within 12 months of the accounting period end.

Preparation checklist

Confirm whether this applies: This guide applies to UK limited companies. Sole traders usually deal with business profits through Self Assessment instead.
Open the relevant HMRC or Companies House account before acting.
Collect records, dates and reference numbers that support the filing.
Set a preparation reminder before the deadline, not only on the deadline.
Save submission receipts, payment references and source links.

Realistic example

A first-time owner reads the Corporation Tax guide after receiving a reminder or official message. They check whether the duty applies, note the relevant date from the official account, gather the records listed in the source guidance and save evidence after filing or paying.

This example is deliberately general because actual dates and duties can change with your company history, tax registrations, accounting period and HMRC or Companies House notices.

Common mistakes

Waiting for the return deadline before thinking about payment.
Assuming Companies House accounts are the same as a Company Tax Return.
Not keeping records that explain income, expenses and adjustments.
Ignoring HMRC letters or online account messages.

Penalties and risk

Late filing, late payment or inaccurate returns can lead to penalties and interest. HMRC guidance explains the current rules and how penalties are calculated.

Common myths

If no money changed hands, no filings can be due.
Companies House and HMRC deadlines are always the same.
A reminder calendar can replace checking the official account.
Filing a form always means any related payment has also been made.

How it links to annual accounts

Company accounts and tax returns use related information, but they are not the same filing. You may need to file with both Companies House and HMRC.

Frequently asked questions

Is Corporation Tax only for limited companies?

It mainly applies to limited companies and some organisations. Sole trader profits are usually handled through Self Assessment.

Is the Corporation Tax payment deadline the same as the return deadline?

Not always. The payment deadline can be earlier than the Company Tax Return filing deadline.

Video explainer

This guide is ready for a 2-minute explainer and 5-minute walkthrough. No video is embedded until Business Sorted has a reviewed transcript that matches the official-source guidance.

Transcript outline

1. What Corporation Tax means.
2. Who should check whether it applies.
3. Which dates and records to prepare.
4. Which official sources to open before acting.

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