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Corporation Tax returns (CT600)

A company files a Company Tax Return (form CT600) for each accounting period, with its accounts and tax computation attached. The return is due 12 months after the end of the accounting period. The tax is usually due earlier: 9 months and 1 day after it.

Source: gov.uk: Company Tax Returns

Source: gov.uk: Pay your Corporation Tax bill

In Fyling you prepare the return, review and approve it, and send it to HMRC under your practice's own HMRC online filing login, with the company's accounts attached.

What Fyling does and does not do

Fyling works the computation from the figures you enter, using the Corporation Tax rates for the period, and shows each adjustment so a reviewer can follow it.

It does not decide what is taxable or which claims to make. You choose each adjustment and relief; your practice approves the return.

How to prepare a return

Open the company, then the Corporation Tax tab. The return has eight steps.

  1. Accounting period.
  2. Figures from the accounts. If the company's accounts for the period are approved in Fyling, the figures are filled in from them. Change one, and it is marked as changed.
  3. Adjustments to profit. Depreciation is added back once, from the accounts.
  4. Capital allowances. Fyling claims the most allowed for each pool, starting from the additions in the period.
  5. Losses, including a claim to carry a loss back to the year before.
  6. Tax calculation, with any marginal relief shown on its own line.
  7. Review. The return is checked, and the company's UTR is filled in from its record.
  8. Approve. Your practice's reviewer and client-approval settings are checked here.

Before a return can be sent

The Submit to HMRC button refuses, and says why, unless all of these are true:

  • The company's Corporation Tax authorisation is recorded on the client's HMRC access & handover page.
  • Your practice's HMRC online filing login is saved for the mode you are in, test or live.
  • The accounts for the same period end were prepared and sent from Fyling. HMRC needs them attached, and Fyling attaches that exact file.
  • Nothing has changed since the return was approved.

After sending

The return page shows HMRC's answer when it comes: accepted, or rejected with HMRC's reason. If Fyling cannot tell whether HMRC received a return, it will not send it again. Check with HMRC first.

Read Connecting HMRC and client authorisation for the authorisation and login steps.

What it does for your practice: Corporation Tax returns