Your firm may get requests from your clients to list or name an additional insured on your Professional Liability policy.  The additional insured language is not available on your Professional Liability policy and there are a few reasons why:

Some clients believe that they are better protected if they are the additional insured on a Professional Liability policy.  The most important point to remember on a Professional Liability policy is that the policy does not make payments to the named insured (your firm) but instead on behalf of the named insured.  For example, if your firm was sued due to a design error the policy pays the claim on your firm’s behalf to your client.

Additionally, your firms client cannot be an additional insured on Professional Liability because they are not performing ‘professional services’ and does not have the risk that a design professional does.

It is more common to have an additional insured on a Commercial General Liability policy for Design Professionals.  There are a couple of ways to accomplish the additional insured on Commercial General Liability: with a blanket endorsement or a scheduled endorsement.  The blanket endorsement is common to have on a Design Professionals Commercial General Liability policy and generally does not require an additional premium.  A schedule endorsement names that specific additional insured (client) and sometimes requires an additional premium.

With clients working with both contractors and Design Professionals it is common to get the additional insured request.  Just be sure that your client understands that the additional insured is not available on your Professional Liability policy.