Collocations for client - noun

big, important, large, major
The company needs to focus on its biggest clients.

new
potential, prospective
current, established, existing, regular
former, old
business, corporate
private
individual
wealthy
celebrity

advise, assist, help, serve, service (AmE)
A new branch has been opened to serve clients in Dallas.

have
find, get
act for, represent
take on
She's so busy that she's not taking on any new clients.

attract
a campaign to attract new clients

on behalf of client
On behalf of my client, I would like to remind you of your obligations in this matter.