"You've got nothing to lose by trying," she says.
But she warns that if you opt out of an existing contract with a company they may also charge an early disconnection fee which should be taken into account when deciding to switch.
Edwards says before picking up the phone to the call centre it pays to do your homework.
"Get quotes from other providers so you know if you can get a better deal elsewhere."
There are easy to use comparison websites for power companies and telcos at Telme and Powerswitch.
If you are an existing customer and you see a better offer for new customers to sign up don't be afraid to ring up and ask if you can also get that deal.
Edwards says many telcos are happy to roll you into a deal which may give more gigabytes to use for the same monthly fee.
It's much harder to negotiate a drop down in the amount you are paying or usage levels.
Accepting an offer from a different power company can also trigger your existing power company to call and try and make a better offer in an attempt to hold on to an existing customer.
Key phrases to include in your conversation with the call centre staffer could include "I'm thinking about canceling", "Is that the best offer you can do?" and "That seems expensive".
If you are not getting much traction pull out the figures from the research you have already conducted.
Don't be afraid to tell them how much less you could pay with a rival company.
With a call centre you may not have to provide proof of these numbers but Edwards says it's important to bear in mind that you could be asked to.
"Don't make empty threats because they they might turn around and say it "sounds like you have got a better deal, we will cancel your contract."
That could leave you with a cancellation charge of several hundred dollars.
You may also have to ask to be transferred up the chain of command as some call centre staffers aren't allowed to offer anything beyond what comes up on their computer systems.
"It doesn't hurt to ask to speak to a manager."
Edwards who originally hails from Britain says haggling isn't as part of the Kiwi culture as it is in other countries but people are starting to do it more.
"In a way you have got nothing to lose by asking, so ask."