Multiple Apple Developer Accounts I've read multiple messages on the subject, but I wondered if anyone had first hand experience (or genuine knowledge one way or another), if it is possible to more than one Apple Developer account? 

As far as I know, you can create one for each Apple ID that you have, but I have not been able to find anything that suggests this is not possible (or breaches any rules). Are Apple likely to be bothered as long as you pay the $99/year for each Developer Account?

There is a link here that seems to suggest that it is possible 

Would appreciate any comments on the subject.

Thanks.
Business Entities and Individuals

If you operate a legally recognised business entity, the business can have an account and you can have a personal account. You will need to associate each account with a separate e-mail address.

Consultants and Clients

If you are a consultant, you should consider one account for yourself and one each for your clients.

Personal Experience

I use multiple Apple Developer Accounts. They are associated either with business entities I am associated with, or are personal developer accounts.

As you mention, each account needs to pay the annual fee.