I would strongly advise that you speak to a membership adviser in the first instance and you can find out who this may be through the following link. https://www.theiet.org/membership/become-a-member/fellow-membership/become-a-fellow/ You don't need to have a managerial role but you will be expected to meet two of nine of the following criteria over a period of five years within the last 10 years. 

-Leadership
- Responsibility
- Insight and Experience
- Creativity
- Innovation
- Enterprise
- Service
- Repute
- Influence and Contribution

I've found that one or two people that I've helped in the past have not read and applied themselves to the clear criteria laid down in the IET website, so that would be my other bit of advice. It is not enough to show that you've operated in a senior role in industry but have "demonstrated recent significant achievement(s)" in the chosen criteria. 

Best wishes in your application,

Mike

Mike Frain said:

the clear criteria laid down in the IET website

To be fair Mike, and only to emphasise your advice which I totally agree with, I'd suggest the criteria aren't totally clear - and can't be as there's so many different possible ways that exceptional contribution to the field of engineering could be shown. So the criteria give good examples of possible ways in which two of the areas listed could be shown, but there will be others. So yes, seeking advice from a Fellowship advisor (and, if you can find them, other Fellows with a similar background to yours) is a good thing to do.

In particular, one thing I struggled with until I got excellent advice, was that working in a large organisation it can be not obvious how you show seniority. I found the guidance would work well for a technical director of a (say) five person company, it was not so clear for someone, as I was, who was responsible for a very significant area of the business (both technical and management / leadership in my case), but was a long way from the top because it was a huge multinational. The key is showing clearly what personal responsibility / authority / influence you carry - and, critically, what impact this has had on your business and/or wider society.

Thanks,

Andy