Especially for those currently working. Sometimes due to work
politics it's not easy to provide a reference.
I think u meant referees.
Whether ur new employer will check out the referees depends on
the nature of work u wil be tasked to do and the new employer HR
policy.
Say this person age 33, worked 6 years in never heard of XYZ
company as a Head Logistics, and he applied to say SIA for the post
of Head Logistics, the referees will be very important. The new
employer will want to confirm the person's previous roles and
responsibilities.
Most dun bother at entry level or even mid management jobs.
However I do know of several companies that even do a phone
interview with the referees.