Deputy Commissioner Michael Clement says police are working with gun-owners to ensure they can safely store their soon-to-be outlawed weapons until they can be collected as part of the uplift programme.
Clement said the new legislation that will become law tomorrow makes big changes to the gun laws in a short amount of time, so licensed gunholders must be patient while police work through the collection process.
"The main change is the prohibiting of a large number of semi-automatic firearms, parts, and large-capacity magazines," Clement said.
"There will be very few exceptions to this - only collectors, dealers, and people who undertake wild animal pest control will be able to apply for exemptions."
"For people who find themselves now in possession of a prohibited firearm, we ask you to please notify us online at the Police website.
"The collection of firearms will occur at a later stage.
"For now, there is an amnesty in place and we ask people to please notify us."
Earlier today, Police Commissioner Mike Bush reiterated there has been no specific threat to Anzac Day commemorations, but police will not budge on the advice to cancel some services around the country.
Bush said while the national threat level remains high in New Zealand not all Anzac Day services can go ahead as previously planned.
"While we understand the advice to consolidate Anzac Day events is disappointing for some people, our priority is public safety and we will not compromise on this.
"In the current environment it is important that people feel safe to carry on their daily business, including attendance at Anzac services.
"Our job is to ensure that people not only feel safe, but are safe."
Bush said the decision to advise some RSAs to consolidate their services was not made lightly.
"We fully recognise the importance of Anzac Day events."
Police's message to anyone attending Anzac services remains one of vigilance - if you see anything suspicious then call police on 111.