Emergency calls to police in Aberdeen will now be answered at handling centres in the central belt.
Police Scotland shut its Aberdeen call centre on Tuesday and all 999 and 101 calls are now being answered at centres in Govan, Bilston Glen and Motherwell.
Staff in the central belt will assess the situation before relaying calls to the North Area Control Room in Dundee, which will dispatch officers.
Concerns have been raised over a potential loss of local knowledge. Police Scotland has struggled to retain staff since announcing plans to centralise its call centres three years ago.
About 80 call-handlers are expected to quit in Aberdeen and Inverness, where the control room is also set to close.
A Police Scotland spokeswoman said: "Following the approval by the Scottish Police Authority last week to transition call handling from the Aberdeen area control room and service centre, final approval has now been given by the chief constable to move ahead with the programme.
"Call-handling will now transition into the North Area Control Room and the National Police Scotland Service Centre."
A scathing report on police call-handling, published following the deaths of a young couple on the M9 in July 2015, included 30 recommendations for improvement.
Assistant chief constable John Hawkins said centralising call-handling facilities would "provide the public with an improved level of service".
"There will be no change to the way the public contacts Police Scotland and they will receive the same service delivered by a local officer," he said.
The Scottish Fire and Rescue Service is also shutting its northern 999 control rooms as part of the formation of a single, Scotland-wide force.
Whistleblowers have warned the closure of call centres in Aberdeen and Inverness will endanger lives and put greater pressure on firefighters.
But chief fire officer Alasdair Hay said centralising services will make people safer.