The short answer is no, as universities and colleges are committed to access to their institutions for their employees as well as their students. If you have suitable work experience, and depending of course on the role you’re applying for, most universities will consider this in lieu or in combination with any other training you may have undertaken or plan to complete.
In my experience, however, a degree is very helpful to working in HE, for several reasons.
1) It shows you have an interest in, and an aptitude for, the central service/product on offer by the university or college you are applying to – education is at the core of their business and their values, and you would be best placed if you can demonstrate the role it has had in your life as well.
2) Higher education is an increasingly complex and dynamic industry, and advanced studies lend themselves to the development of critical thinking and problem-solving skills that are valued in that kind of environment. Having a degree doesn’t necessarily mean you’re going to be a flexible, adaptable, pro-active employee, but it may show that you have a pre-disposition towards this.
3) Working with others who have advanced degrees and/or who are at the top of their field – you won’t automatically be able to get the respect you deserve from a fellow staff member just because you’ve got some letters behind your name, but when you’re working in a place that places a great deal of importance on teaching and research, you may find it easier if you know your quantitative from qualitative evidence, and are able to demonstrate this tangibly not only from your professional working history, but also from having taken appropriate courses at some stage in your career.
All of this will of course depend to a certain extent the role that you have as well as your relationship with your peers and of course the institutional culture where you work. But in my experience, you will likely find it easier to get settled in a new role if you have had some prior experience of university-level study and how a university organizes itself. And certainly as a hiring manager, with all else being equal, I would certainly prioritise an applicant or a candidate for promotion who showed a continuing interest in their own personal and/or professional education, and would certainly encourage him or her to take courses at the institution.
Another option to consider is joining professional networks and memberships. Most professionals working in higher education (on either the academic or administrative side) hold multiple memberships of relevant professional organisations, which are also selective and often also require studies at an appropriate level in order to gain membership.
There may be a “degree” of academic snobbery at work here, in that members of the academy expect that others in the organisation should have achieved a similar standard of education. But when you think about it in terms of an institution’s brand values and mission in society, what does it say if they conclude a degree isn’t important to success?