Are Accounts Submitted to HMRC with the CT600?

When you submit your CT600 through TinyTax, the documents HMRC needs are included in the same submission automatically. Exactly what is included depends on the filing option you choose and whether your company is trading or dormant.

What the HMRC CT600 Submission Includes

For a trading company, clicking Submit Corporation Tax to HMRC packages three documents into a single electronic filing regardless of whether you also file to Companies House:

1. CT600 form — the structured tax return
2. Tax computation — an iXBRL document showing how the taxable profit was calculated
3. Company accounts — an iXBRL set of accounts (profit and loss, balance sheet)

HMRC receives all three together. There is no separate step to attach computations or accounts — TinyTax handles this automatically.

Dormant companies are an exception: HMRC does not require accounts or a tax computation alongside the CT600 for dormant periods. TinyTax handles this automatically and does not attach accounts to dormant CT600 submissions.

What Goes Where

TinyTax Filing Option	What goes to HMRC	What goes to Companies House
CT600 and Accounts (trading)	CT600 + computation + accounts (iXBRL)	Accounts
CT600 only (trading)	CT600 + computation + accounts (iXBRL)	Nothing (you file CH separately)
CT600 (dormant)	CT600 only — no accounts required	Nothing
Accounts only	Nothing	Accounts

The CT600 only option is for when you have already filed your accounts with Companies House yourself. TinyTax still includes the iXBRL accounts in the HMRC submission — it simply does not also file them to Companies House.

Are the HMRC and Companies House Accounts the Same?

When you choose CT600 and Accounts, TinyTax generates a single set of iXBRL accounts used for both HMRC and Companies House. Both authorities receive identical figures.

If you later refile your CT600 following a correction, the iXBRL accounts attached to the new submission are regenerated. If Companies House has already accepted an earlier version, you should amend your Companies House accounts to match. See: How to Amend Companies House Accounts.

Why Capital and Reserves May Change After a Recalculation

Capital and Reserves is a derived figure — not entered manually. It equals Share Capital plus Retained Earnings, where retained earnings includes the post-tax profit. If your tax calculation changes, the tax charge changes, which flows through to retained earnings and therefore Capital and Reserves. This is expected behaviour.

Common Scenario: Already Filed Accounts to Companies House

If you filed accounts to Companies House through another route and then used TinyTax for your CT600:

• Companies House: Already covered
• HMRC: Covered by your TinyTax CT600 submission — accounts are automatically included in the HMRC filing even when you chose CT600 only

You do not need to take any further action.

Common Questions

Does my CT600 go to Companies House?

No. The CT600 (Corporation Tax return) goes exclusively to HMRC — Companies House does not receive it. In summary:

• CT600 + tax computation + iXBRL accounts → HMRC (for trading companies)
• Company accounts → Companies House (when you choose CT600 and Accounts or Accounts only)

If you have already filed your accounts with Companies House and now want to file the CT600, choose CT600 only in TinyTax.

How do I file my CT600 through TinyTax?

1. Log in to your TinyTax dashboard
2. Find your company in the list and click Start Filing
3. If accounts are already filed with Companies House, choose CT600 only
4. Work through the filing form, entering your income and expense figures
5. On the Review & Submit page, review the CT600 and tax computation
6. Click Submit Corporation Tax to HMRC to file

TinyTax submits directly to HMRC on your behalf — you do not need to take any separate action on HMRC's website (only your Government Gateway credentials are needed at the point of submission).

How do I know what was included in my HMRC submission?

If your CT600 status shows Accepted in your dashboard, your submission was accepted by HMRC. You can download the submitted documents from the dashboard to confirm exactly what was sent.

Do I need to file accounts to Companies House separately after using CT600 only mode?

Yes — if you chose CT600 only, you still need to file accounts to Companies House through another route (Companies House WebFiling, accountant software, etc.) if you have not already done so. TinyTax CT600 only does not file to Companies House.

My Capital and Reserves figure changed after I refiled — is this correct?

Yes, this is expected. Capital and Reserves is automatically calculated and reflects the corrected tax position. If your Companies House accounts show the old figures, you can amend them. See: How to Amend Companies House Accounts.