Self assessment confusion - PAYE for 15+ years yet registered for SA


Hi there, long time reader of the site and forums but a new poster. I hope this is in the right section.
I created an online tax account over the weekend to check my national insurance contributions.
While doing so I see I have a UTR number and am registered for self assessment. Please note i've been PAYE for over 15 years in my current job and 2 years in a job prior to that. PAYE info on the HMRC gov site shows correct for 2018 up to the current year.
I believe the registration might be historic from being self employed for a brief spell early 2000's and filing tax returns back in 2005 if memory serves. I honestly don't remember if I informed HMRC I was no longer self employed however I went bankrupt in 2007 and a portion of the debt was to HMRC, not sure if that is relevant.
I worry i've missed something. I struggle with what you might call high functioning anxiety and this has made me extremely worried over the weekend. I've obsessively spent hours and hours searching different articles and each one suggests I do not fill any of the criteria which means I have to submit a return.
Enough waffling, I apologise - my question essentially is does being registered for self assessment mean you automatically have to submit one each year or only if/when the need arises? I can't remember the last time I had a letter from HMRC, let alone a letter asking me to submit a tax return.
Replies
Feel like an idiot for stressing over this all weekend.
(Ha sido divertido)
When an individual goes bankrupt, they are issued with a new UTR, so if you were not self employed at that time, that may be why you haven't been asked to complete a return. See:
https://www.gov.uk/hmrc-internal-manuals/self-assessment-manual/sam106030