Tax - Companies House WebFiling Service Ending — How to File Accounts | @AdamsWinter Support

Companies House WebFiling Service Ending — How to File Accounts

The Companies House WebFiling service for accounts is closing on 31 March 2026. After this date, companies can no longer use WebFiling to submit annual accounts. This guide explains what changes and how to file accounts with @AdamsWinter going forward.

What Is Changing?

Companies House is ending the WebFiling service for annual accounts. From April 2026, accounts must be submitted in iXBRL format — the old WebFiling upload no longer works for accounts.

The confirmation statement (annual return) is not affected — you can still file that through Companies House WebFiling or directly on the Companies House website.

What @AdamsWinter Can Replace

@AdamsWinter replaces WebFiling for annual accounts filing:

  • Micro-entity accounts (FRS 105)
  • Small company accounts (FRS 102 Section 1A)
  • Dormant company accounts
Your accounts are generated in the required iXBRL format and submitted directly to Companies House.

Accounts Only vs CT600 and Accounts

When you start a filing in @AdamsWinter, you choose what to file:

  • Accounts only — files your annual accounts to Companies House. Use this if you only need to replace your WebFiling accounts submission.
  • CT600 and Accounts — files both the Corporation Tax return to HMRC and your annual accounts to Companies House together. Most active limited companies need both.

Do I Need to File a CT600 as Well?

Whether you need a CT600 depends on whether HMRC has registered your company for Corporation Tax. The key question is: does your company have a UTR (Unique Taxpayer Reference)?

A UTR is a 10-digit number sent by HMRC when a company registers for Corporation Tax. It appears on any HMRC correspondence addressed to the company. This is separate from your personal Self Assessment UTR.

  • If you have a company UTR: HMRC expects an annual CT600, even if your company has no taxable profit. Use the "CT600 and Accounts" option in @AdamsWinter.
  • If you do not have a UTR: You may not have been registered for Corporation Tax. Contact HMRC to confirm your position: 0300 200 3410.
ℹ Right To Manage (RTM) companies and flat management companies are limited companies and may need to file CT600 even if they have no taxable profit. A nil or dormant CT600 still needs to be submitted if you have a company UTR.

What You Will Need

To file accounts through @AdamsWinter, you will need:

  • Your Companies House authentication code — the 6-character code used for WebFiling. You can find this by signing in at Companies House, or request a reminder to be posted to your registered office.
  • Your company's balance sheet figures (assets, liabilities, equity at the period end)
  • Your company's profit and loss figures (income and expenditure for the period) — unless filing as dormant

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