Is the following phrase grammatically correct

[Anonymous]

Our management team are certified Business Coaches.

[Casiopea]

Our management team are certified Business Coaches.

Test #1
If we add 'members' after the word 'team', like this,

Our management team (members) are certified Business coaches.

it's evident the subject is plural, so the verb should also be plural, are.

Test #2
If we replace the subject 'Our management team' with a pronoun, like this,

We are certified Business coaches.

it's evident the subject is plural, so the verb, too, should be plural, are.

Test #3
Note that, the verb 'are' is a linking verb. 'are' is a form of the verb To Be. Such verbs link the subject with its object, known as a subject complement. If the object is plural, then the subject should be plural, like this,

We are doctors. (OK)
We are doctor. (Not OK)

We are coaches. (OK)
We are coach. (Not OK)

Our team are Business coaches. (OK) 'Our team' means, members.
Our team is Business coaches. (Not OK)

All the best, :D