Introducing Filing Amendments: Correct Your CT600 and Companies House Returns with Ease

Mistakes happen. Whether it's a transposed figure on your profit and loss statement, a missed expense category, or an updated balance sheet entry — errors in your CT600 corporation tax return or Companies House annual accounts can have real consequences. Late corrections may attract penalties from HMRC, and inaccurate filings at Companies House can affect your company's public record. Under Schedule 18 of the Finance Act 1998, companies have the right to amend their CT600 returns — but only within a strict window. HMRC allows amendments within 12 months of the original filing deadline. After this window closes, corrections become significantly more complex and may require an HMRC enquiry. Until now, correcting a submitted filing meant navigating complex government portals or relying on your accountant to handle the process manually. With WeFile's new amendment feature, you can correct and resubmit directly from the same intuitive wizard you used for the original filing — no external tools required.

WeFile's amendment feature covers the full scope of corrections you might need to make. You can amend your CT600 Corporation Tax Return (HMRC) to correct turnover figures, expense allocations, capital allowances, tax computations, and any other entries on your corporation tax return. You can also amend your Companies House Annual Accounts to update your profit and loss statement, balance sheet figures, notes to the accounts, and director information. If your error affects both submissions — for example, a balance sheet correction that also changes your tax computation — you can amend both simultaneously in a single workflow. Unlike the original filing where both CT600 and Companies House are pre-selected, amendment filings start with nothing selected. This gives you full control over exactly which submissions need correcting, so there's no need to resubmit filings that were accurate the first time.

Filing an amendment in WeFile is straightforward. From your filing history, simply select the filing you need to correct and click "Create Amendment". This creates a new amendment filing linked to the original submission. Here's the step-by-step process: 1. Choose What to Amend You'll be presented with the option to amend your CT600 (HMRC), your Companies House accounts, or both. Select only the submissions that need correcting. 2. Review and Update Your Figures The amendment wizard pre-populates all your original data — profit and loss, balance sheet, account type, and credentials. Simply navigate to the relevant step and make your corrections. There's no need to re-enter everything from scratch. 3. Review Your Changes Before submitting, the summary step presents a clear overview of your amended filing. Double-check your corrections and ensure everything is accurate. 4. Submit the Amendment Once you're satisfied, submit the amendment. WeFile generates the corrected CT600 XML or iXBRL accounts with the appropriate amendment taxonomy tags and submits them directly to HMRC and/or Companies House on your behalf.

We've designed the amendment flow to be as clear as possible. Throughout the wizard, you'll see tailored descriptions and info banners that distinguish the amendment process from a standard filing. CT600 amendments are clearly labelled as "Corporation Tax Return Amendment" submissions to HMRC. Companies House amendments are labelled as "Annual Accounts Amendment" submissions. Warning banners about already-filed accounts are suppressed for amendments, since you're intentionally refiling. HMRC gateway activation notices are also hidden — if you've already submitted the original, your gateway is already active. The amendment wizard uses the same familiar interface as the original filing wizard. If you've filed with WeFile before, you'll feel right at home — the only differences are the amendment-specific labels and the flexibility to choose which submissions to correct.

When you submit a CT600 amendment, WeFile generates a revised CT600 XML document and transmits it to HMRC via the GovTalk channel, just like the original — but flagged as an amendment. The CT600 XML is packaged in the amendment-specific envelope format that HMRC requires. For Companies House, WeFile generates revised iXBRL annual accounts with the correct amendment identifiers embedded in the taxonomy. This ensures Companies House recognises the submission as a correction to a previous filing rather than a duplicate. All amendment submissions go through the same real-time polling and status tracking you're used to, so you'll know exactly when your corrected filing has been accepted. You can monitor the progress from your filing dashboard as the system moves through saving, submitting, and polling stages.

You should consider filing an amendment if you discover an error in your profit and loss or balance sheet figures after submission, if you need to reclassify an expense or income category, if your corporation tax calculation was based on incorrect figures, if you received updated information (such as a revised invoice) that affects your accounts, if you identified a prior-period adjustment that needs reflecting in your filed accounts, or if HMRC or Companies House has queried your original submission and requested a correction. It's important to file amendments promptly. HMRC allows amendments to CT600 returns within 12 months of the original filing deadline, so don't delay if you spot an issue — the sooner you correct it, the better. For Companies House, there is no formal statutory deadline for filing amended accounts, but corrections should be submitted promptly to keep your company's public record accurate.

Here are some of the most common reasons our users file amendments. Correcting a Turnover Figure Perhaps you included a draft invoice that was later cancelled, or omitted revenue that arrived before your year-end. Updating turnover flows through to your tax computation automatically in WeFile, so the amendment recalculates your corporation tax liability based on the corrected figures. Reclassifying Expenses If an expense was posted to the wrong category — for example, motor expenses recorded as office costs — you can correct the profit and loss allocation. This may also affect your corporation tax liability if the reclassification changes your allowable deductions. Updating Capital Allowances Discovered an asset that qualifies for Annual Investment Allowance (AIA) or was missed from your original claim? Amending allows you to reclaim the correct amount and reduce your tax bill accordingly. Responding to HMRC Enquiries If HMRC opens an enquiry and requests corrections, filing an amendment through WeFile provides a clear audit trail and ensures the revised figures are properly submitted through the official GovTalk channel.

Amendments are treated as standard filings within your WeFile plan. If you're on the Yearly Accountant Membership (£250/year), each amendment counts towards your 100-filing allowance. There is no additional charge per amendment beyond what you'd pay for a regular filing. Pay-as-you-go users are charged at the standard per-filing rate. For API subscribers (£500/year), amendments can also be submitted programmatically through the existing filing endpoints — simply flag the filing as an amendment when creating it via the API. Amendments count towards the 300-filing API allowance. There are no hidden fees or surcharges for filing amendments. The cost structure is identical to a standard filing, regardless of whether you're correcting a CT600, Companies House accounts, or both.

Can I amend a filing more than once? Yes. You can file multiple amendments to the same original filing, provided you're still within HMRC's 12-month amendment window for CT600 returns. Will my original filing be overwritten? No. Your original filing remains in your history alongside the amendment. WeFile maintains a complete audit trail of all submissions, so you can always refer back to the original figures. Do I need to resubmit both CT600 and Companies House? No. You choose exactly which submissions to amend. If only your Companies House accounts need correcting, you can amend those alone without touching your CT600. How long does it take to process an amendment? Amendment processing times are the same as original submissions — typically a few minutes for HMRC and a few hours for Companies House. You can track the status in real time from your filing dashboard.

Ready to correct a filing? Here's how to get started in three simple steps: (a) Head to your Filings page and find the submission that needs amending. (b) Click "Create Amendment" to launch the amendment wizard. (c) Make your corrections, review, and submit. If you have any questions about the amendment process, our Help Center has detailed articles, or you can reach out to our support team via the ticket system. We're committed to making corporation tax filing as painless as possible — and that includes making corrections simple when things don't go perfectly the first time.