Period End Date Warning — Not the Last Day of the Month

When you click View Draft Submission on the CT600 form, TinyTax checks whether your period end date falls on the last day of a month. If it does not, you will see this warning:

> The period end date (DD Month YYYY) is not the last day of the month. Most companies use month-end dates (e.g., 31 October, 30 April). Please verify this date is correct before proceeding. > ⚠️ Click Submit again to proceed if you have verified the information above is correct.

This is not an error

The warning does not block your filing. It is a soft prompt to confirm that the date is intentional — some companies do have accounting periods that end on a non-month-end date, and that is perfectly valid.

How to proceed

1. Verify that the period end date shown is correct for your company (check your Companies House accounting reference date or your HMRC Notice to Deliver if you are unsure)
2. Scroll down to the View Draft Submission button at the bottom of the form — this is the same button you already clicked
3. Click View Draft Submission again
4. The warning will not appear a second time and the form will proceed to the preview page

Why does the button say "Submit again"?

The warning message refers to clicking your submission button again. On the CT600 form, that button is labelled View Draft Submission. Clicking it a second time tells TinyTax you have verified the date and want to continue.

When should I change the date?

If the date shown is wrong — for example, your company year-end is actually 31 March but 20 March appeared by mistake — go back and correct it before proceeding. Use the period end date field on the form to enter the correct date.

If the date is correct (some CICs, charities, and companies with custom accounting reference dates do use non-month-end dates), simply click View Draft Submission again.