As at June 30 last year, the company had 852,679 customers but that number fell to 816,135 by December 31.
Ms Way declined to divulge the number of Sky customers in Northland but said 45 per cent of all households would be subscribers.
As at the last census in 2013, there were 60,192 occupied homes in Northland.
"There's a lot of competition out there so we need to spend our money where the greatest impact to our customers is and we're always looking for new content but they don't come cheap.
"Loss of customers and the difficulty to attract and retain them has limited the amount of revenue coming through."
People took to the Northern Advocate facebook page to vent their anger at the closure of the office which has operated for 20 years.
Lissa Charlaine Manukura-Rihari said: "So all your Northland customers aren't as important as your Auckland & Wellington customers? Maybe we need to look at changing service providers."
Raewyn Colin Hurst said "you would think with all the money it charged, Sky would have an office in every town".
A Sky customer who arrived at the Whangarei office yesterday to pay his bill said the closure would be a blow to people like him who preferred to discuss issues face to face rather than on the phone.
"It's always good to come into the office and talk to them than to wait for ages on the phone. I pay $167 a month and now I have to go to the Post Office," he said.
For queries, Northland subscribers will now have to call Sky's customer services team on 0800 759 759 or go on to its website.
Decoders can be returned to Cobble Key Trophy and Gifts in John St.
Ms Way said there would not be any impact on the technical side of things such as installation of Sky dishes and callouts for technicians.
Nelson and Dunedin offices have also been closed.