Banks are competing for home loan business with offers of cash - and even some people who stay with their current banks are getting them, brokers say.

Glen McLeod, head of Link Advisory, said an increasing number of lenders were offering cash back incentives for people who were taking out new home loans.

That could be people purchasing a new property or shifting from another bank.

He said the amount offered could vary up to 0.9 percent of the loans value, usually with a cap of $20,000.

McLeod said it was good for competition in the market.

David Cunningham, chief executive at mortgage broking firm Squirrel, agreed 0.9 percent was standard.

"Refinancing when your fixed rate loan comes up makes sense, it's a bit of pass the parcel... I steal one of your customers and pay $10,000, you steal one of mine and pay $10,000..."

He said banks liked cashbacks because usually existing customers would not get them.

That limited the cost for the bank.

"If you have a really competitive fixed rate, all your existing customers get it so you reprice your whole portfolio. Cashbacks are just rewarding the person who's prepared to move."

Cunningham said they were less common in periods when bank margins were tighter.

A spokesperson for ANZ said there was a lot of activity in the market, including customer switching between banks.

"The Reserve Bank recorded a record amount of bank switching in December, with just over $2 billion - roughly a quarter of new lending - changing hands between lenders including non-banks. As part of that cashback offers are popular.

"ANZ does offer customers the ability to receive a cash contribution towards the costs of their housing transaction like solicitor or valuation costs, however the amount can vary depending on the elements of the loan and eligibility criteria applies."

McLeod said people could sometimes apply for retention cash back when they were refixing a home loan, in return for agreeing not to move to another bank.

"However, if the loan is in its infancy, typically within the first three to four years, it may not be eligible due to the initial cash-back offer period."

Cunningham said that was less common.

"The moment you start giving cashback to customers to stay you get everyone on the phone saying 'I'm going to leave'. It's a slippery slope."

McLeod said people needed to understand some of the conditions that could come with a cashback.

"If a client chooses to switch lenders within a certain time frame, they might be required to repay the cash-back amount in full or proportionally, depending on how long they have been with their current lender. While the immediate financial benefits of such incentives are undeniably attractive, we encourage borrowers to consider the long-term financial implications carefully, whether the loan structure supports their current circumstances and financial goals, and the details of the offer, particularly the eligibility criteria."

-RNZ