I completed my funded PhD last year. I'm now working outside academia, which is great btw. I would like to publish at least one article on PhD findings in a peer reviewed journal. Do I need to contact my former university or supervisor (we've not kept in touch) if the article is accepted for publication? Or is it sufficient to state where I undertook the PhD in the author bio section of the article?

Contact your supervisors first. If there name is going to be attached to the paper they need to approve it,read it etc. Also, some papers have charges, you need to figure out who is paying that, it can range from a couple hundred euro to a couple of thousand.

It depends. It could be helpful to have them review the manuscript before you submit it. Or indeed if might be common in your field to invite the supervisor to coauthor. If neither of those things are relevant then you could go ahead and do it yourself. It is definitely sufficient to say it was your PhD work in the bio. You might want to acknowledge supervisors by name if they gave helpful feedback on the work.

But if it is the norm in your field/area/old department to coauthor with the supervisor, or if you feel they did contribute to producing that piece of work, then I think it would be good etiquette to contact them and let them know you are planning to submit it for publication.

Even if it's normal in your area to be the sole author on PhD work (I know it can be), it might still be beneficial to contact them and ask if they would comment on a draft or have suggestions (e.g., you are at an earlier stage and wondering which findings might make a good paper and could do with support). But that would be if you felt it was helpful.

Many thanks for these helpful replies. In my field it is the norm to be sole author and there are no charges for publishing. If I thought I would benefit from feedback from my former supervisor, I would share a draft, but sadly Im not sure I would find it helpful. I found the relationship pretty difficult and I'm not keen to enter into dialogue with them again. Thanks for your advice - it's helped me to decide how to proceed.

You're welcome. Wishing you a smooth submission process and swift turnaround :)

If you didn't maintain a good relationship with your PhD supervisor and you don't think they have contributed to your work, then why contact them again. Then the only thing you need to think about is whether to add them in the acknowledgements. You are outside academia now, and your PhD supervisor can no longer influence your future, so you don't need to fear them any more.