Immigrants waiting for news on their visas expiring on September 25 have been told they can use a media release to show employers they are still eligible to work.

Six-month visa extensions for many workers were announced in July, and a month later their partners' and children's visas were added.

But an immigration adviser, Toni Alexander, said the visas have not all been issued and, as many were previously extended to 25 September under the Epidemic Management Notice, they expire tomorrow.

Immigrants have also approached RNZ with their concerns about the delays in communication and visas being issued.

"The extension is meant to be automatic but they can't electronically automatically extend them - they have to do it manually," Alexander said.

"Still a number of them have not been extended. Tomorrow is the date when most of these expire. When we call immigration on the call centre we're told not to worry, they can still work and attend school, and we should just show employers and schools their media release that their visas will be automatically extended. But the employers still cannot allow staff to work on an expired visa."

The implications were huge, including not being eligible for publicly funded health care, she said. If that happened when an immigrant was pregnant, the minimum they would get charged was $9000.

"The ones that I have got extended that were just sitting there, I've had to push and push and really bother people at immigration and it's not productive use of their time, or my time," she said.

"Through their lack of action they are making these people illegal. If they leave and they don't have a legal visa they then show as being illegally present in New Zealand and it can actually jeopardise their whole future travel opportunities."

In one case she had dealt with, one man's work visa had been extended, but not his wife's, nor the children's visas.

"And when they extend them, the only evidence is an email from immigration to say your visa has been extended. When I checked on the visa verification service, there was nothing to show that the visa had been extended. I have an email from the immigration manager that my client can show his employer.

"He has a wife and two children, all of whom, at midnight tomorrow, will become illegal if they can't extend their visas. So, the wife can't work and their income is instantly halved."

INZ working as quickly as possible

Immigration New Zealand (INZ) said visa holders could be assured all visa extensions are legally effective from the date a Special Direction is signed by the Minister of Immigration.

It says it is working as fast as possible to apply the new expiry dates to eligible work and visitor visas.

"As a result of Covid-19, INZ is processing a high volume of changes to thousands of visas and is working to apply new expiry dates as fast as possible," an INZ spokesperson said.

"We have also applied new expiry dates to visitor visas for nationals of non-visa waiver countries that are eligible for an extension, as per the Minister of Immigration's Special Direction on 4 September 2020.

"However, given the high number of recent visa changes impacting many tens of thousands of visa holders, we are currently experiencing a delay in applying the new expiry dates to visitor visas from visa waiver countries in our IT system. We are working to resolve this issue as soon as possible.

"We understand that this may be stressful for eligible visa holders. If they have any concerns about their immigration status or visa expiry date, they can contact us for clarification."