More than 9,000 New Zealand health practitioners - the majority of them nurses - have registered to work in Australia in the past year.

The Trans-Tasman Mutual Recognition Act allows for certain types of health workers registered in Australia or New Zealand to apply for registration in the other country through a streamlined registration process.

The Australian Health Practitioner Regulation Authority says it's seen a "significant increase in applications" in the past 12 months.

Data in its Annual Report shows it approved 9,129 in the 2022/23 financial year - up from 3,562 in 2021/22.

Nurses accounted for 7,848 applications, followed by 540 physiotherapists. The rest was spread across a further ten professions.

Nurses Organisation Kaiwhakahaere Kerri Nuku says the number of people heading to Australia is made up of several groups.

She says we're seeing an increase in international nurses registering here, but using it as a springboard to go and get registered in Australia.

Nuku is also aware of people heading across the ditch to work short-term contracts but aren't settling there.

She says as a result, it's difficult to pinpoint exactly what the flow is.

But, there are many things incentivising homegrown nurses to look further afield. Nuku says with a global shortage of nurses, those graduating here who are not happy with our system can look at opportunities abroad.

She says as soon as Australia got out of Covid, efforts were made across New South Wales and Victoria to invest in a nursing workforce to protect the community for future pandemics, with initiatives to recruit and retain, and that may have seen an increase in interest.

There's also been the introduction of safe staffing legislation in Australia.

"So there's lots more protection perhaps that Australia is offering that nurses are really excited by, potentially," Nuku said.

She says there's a list of things we need to do to stem the flow, including pay equity, ensuring safe staffing, and fully resourcing the workforce.

Nuku says longer term, we need to look at recruitment and make sure we support students thinking about nursing into the profession.

"There are a number of things we have to go through to incentivise and, in many ways, Australia is ahead of the game on that than us."

She says it's a shame we can't work proactively to retain our nurses, and is calling on the Government to step up.

"The Government has to be really strong around bringing out a workforce strategy that is about retention, maybe that's a signal to the Government that we've got to do more."

Physiotherapy New Zealand President Kirsten Davie says the shift to Australia by physiotherapists is driven by more desirable conditions - particularly pay.

Like nurses, a chunk will also be international physiotherapists taking advantage of the pathway into Australia.

Davie says physiotherapists' pay needs to recognise the important role they play in the health sector.

"It's very important those funding models are looked at and reviewed in a very timely fashion by the incoming Government."

She says a new graduate can earn around $30,000 a year more in Australia, compared with in New Zealand.

Davie says a recent pay equity settlement for hospital physiotherapists will have reduced that gap for them, but it remains for those working in the community and primary health.