Filing CT600 for a Historical Period Not Showing on the Dashboard | TinyTax Support

Filing CT600 for a Historical Period Not Showing on the Dashboard

If HMRC has told you there are outstanding CT600 returns for an older period that does not appear on your TinyTax dashboard, you can file them using the custom dates flow.

Why the Period May Not Appear

The TinyTax dashboard shows filing obligations based on Companies House records. There are two common reasons a CT600 period might not appear:

  1. First extended accounting period — If your very first accounting period was longer than 12 months, HMRC splits it into two CT600 obligations (the first 12 months plus the remaining days). Companies House records show a single accounts period, so only the accounts obligation may appear on your dashboard — not the two CT600 obligations HMRC created.
  1. Historical periods filed before joining TinyTax — Obligations for periods already satisfied externally are sometimes not imported.

How to File a CT600 for a Period Not on the Dashboard

Use the custom dates link below to start a filing with your own period dates:

``` https://tinytax.co.uk/submission-form.php?company_id=YOUR_COMPANY_ID&period_start=YYYY-MM-DD&filing_intent=ct600&edit_dates=true&custom_dates=1 ```

Replace:

  • `YOUR_COMPANY_ID` with the numeric ID shown in your dashboard URL when viewing that company
  • `YYYY-MM-DD` with the start date of the oldest period you need to file
Set the period end date in the form that opens.

If accounts were already filed at Companies House separately, use `filing_intent=ct600` (CT600 only). If you need both CT600 and accounts, use `filing_intent=both`.

Extended Periods: Let TinyTax Handle the Split

If the full accounting period was longer than 12 months, enter the full period dates (e.g. 2 February 2021 to 28 February 2022). TinyTax will automatically split it into two CT600 submissions — one for the first 12 months, one for the remainder — exactly as HMRC requires.

ℹ You only need to enter the figures once. TinyTax apportions profits and capital allowances across the two sub-periods automatically.

Alternatively: Use the Dashboard Drawer

From the dashboard, click Start Filing next to any period, then look for the CT600 with custom dates option in the drawer. This opens the same custom dates form without needing the URL.

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