Ltd Company dormant before trading

Hi,
Just wondering if anyone can help with this:

Limited company was incorporated May 2019.
No trading activity till early December 2019.

Current Accounting Reference Date end May 2020.

Company wants to submit Corporation Tax return for period 1st December 2019 to end November 2020.

Company director doesn’t know how to go about doing this.

We’ve found this page:

But getting very confused about who to tell - HMRC or Companies House.

Any advice appreciated!

First things first. Did you notify hmrc the company was dormant?

What you need to do if you wish to file a tax return for the period of trading activity is first submit a form to companies House to reduce the accounting period to 30th November 19. You then need to prepare a set of dormant accounts for that period.
Then you will be able once the form is accepted and the dormant accounts are filed, to prepare a set of accounts from Dec 19 to Nov 20.

If you notified hmrc the company is dormant they won’t expect a tax return until you prepare the trading accounts dated December to nov 20