Whilst it's always a good idea to set up your own Google Analytics account in order to retain ownership of your brand when you start working with other professionals you may want to provide them with access to do work on your behalf. Google provides a great article on how to do this https://support.google.com/webmasters/answer/2453966?hl=en
It's recommended that for Webmasters and SEO personnel they are given Full User access as that allows them to do most things on your behalf but not to add new users and does not confer ownership of your Google Analytics account to them.
If you're working with me please ensure that you provide this access for SEO Services and to allow Webmaster work to be done (e.g. submitting your sitemap to Google).