New rules for tenants and landlords come into force today, bringing an end to 90-day tenancy terminations without justification.

The reform is being dubbed the biggest shake-up for landlord-tenant relations for decades.

There are three phases to the reforms - the first came in on August 11 last year, which meant landlords could only increase the rent once a year.

The new rules coming in today are the second phase, while the third phase, which will allow tenancies to be terminated if family violence or landlord assault has occurred, will come in on August 11 this year.

The second phase, however, is the most substantial of the three.

It means tenants will be able to make minor changes to the property - for example replacing curtains, or hanging up pictures - and landlords can't decline it.

All rental properties will have to show a rental price, so tenants can't bid on them - which often drives the price up.

Additionally, name suppression will be available to those who are successful at the Tenancy Tribunal, avoiding renters who have taken their landlord to the tribunal to be blacklisted.

Real Estate Institute of New Zealand (REINZ) chief executive Bindi Norwell says the new RTA (Residential Tenancies Act) changes will try to get more balance between the tenants and the landlords.

"Quite frankly, they were very outdated and so they needed to be reviewed.

"So I think what they've done is made it easier for tenants and built up quite a few of their rights."

One of the most significant changes is the ending of 90-day tenancy terminations without justification.

"Previously, a tenant could be evicted on a 90-day notice, if they were damaging the property, or they weren't respecting the property, or not paying their rent," says Norwell.

"The landlord had the power to be able to evict them, and this just allowed them to have more control over the property.

"What's happening now is they've removed that, so now a landlord needs to provide three levels of evidence over a three month period to prove that tenants are not treating their property properly.

"Then they can go through a process with the Tenancy Services to actually get them evicted."

-RNZ