Filing Self Assessment if the year in question has not been issued by HMRC

Please can you advise if we can file self assessments if the year in question is not issued or do we need to contact HMRC to open the year before we file? Thank you

Hi Robert 
You can send a return for a year that has not been issued, but any such return received will take longer to process.
Requesting to file for a year reduces the time taken to process your return and make any repayments due available -
to do so, contact us by webchat or phone via Self Assessment: general enquiries
Thank you.

Dear HMRC, this process has worked well in the past but in recent days we have been advised on the webchat that this option to request a return is no longer possible and an SA1 needs to be prepared. This seems to counterintuitive, as we already have UTR and SA account, it has just been made dormant by HMRC. Please can you confirm that it is still possible to use the webchat or telephone to get these accounts made active again?

Hi,
The SA1 is used to register for self assessment, if you are not self employed and have never been registered for self assessment before.  
If you have a self assessment record, which is dormant, all you need to do is contact our self assesment helpline on 0300 200 3310 or webchat facility at:
Contact HMRC and stating why your record needs reactivating.  
Thank you.