Government Gateway

In the context of the group of companies for which I work, I have separate government gateway style logins to use on HMRC.gov for each company.

Is it possible to arrange things so that I only have one login, and then associate different actions with it?

Have I missed a trick somewhere - when Government gateway started, I rather naively assumed each person would manage all these tasks with their own gateway number.

Feel free to flame if I have got completely the wrong end of the stick. Surely those of us in practice must accumulate huge numbers of logins,

Thanks all,