Statutory letter - non resident

Hi, I received a statutory letter with my UTR number for my LTD company. I’m a non resident and still didn’t start a business activity. If I understand correctly, it says that within 3 months of starting a business activity (meaning starting to receive income?), I need to go to HMRC website and apply for tax? Do I understand it right? Is there anything else I should do?

Hi,
Please see the information here 
Corporation Tax: trading and non-trading
It's from when it is active which is starting to receive income.
However, we will assume this is from the date you registered the company.
You will need to tell us if the active date is later than the incorporation date to allow us to note any period as dormant. 
You will need to register for a Government Gateway account to file your company tax returns. You can do that here: 
HMRC online services: sign in or set up an account
Please see under Organisation Accounts.
You'll need to add Corporation Tax to the services you want to use once registered. 
Please note the first Company tax return is due on or before twelve months following the end of the first accounting period.
You will need to check Companies House for their filing requirements which are completely different to HMRC's.
Thank you.

Hi, I still didn’t start a business activity, I’m still working on my website, business bank account etc. So, if I understand right - I need to register an account here: https://www.gov.uk/log-in-register-hmrc-online-services/register ? Do I need to register now or later, when I start a business activity? Also, how will I tell you when I start a business activity? Where can I notify you about that?

Hi,
Because you appear to intend trading soon, and as we've already created a Company Tax record, you don't need to specifically tell us when you actually start trading. 
The Company tax record will have the date of incorporation as the start date, if you don't start trading for some time then it might be worth telling us that from incorporation date to X date you weren't trading so we can note that particular period as dormant.
However, if you intend trading soon (after website & bank sorted) then it might be as well to leave the start date as the incorporation date and complete the first Company tax return for the first twelve-month period but just include income from the date the activity started (ignoring the non-activity period).
You can register for a Government Gateway account now, but you won't need to complete the first company tax return until after the first accounting period has ended.
This is usually twelve-months from the start date, you then have twelve-months following that to file the return.     
Thank you.