"A lot of people stick that licence in their wallet or in a cupboard somewhere and they forget it's got an expiry date."
Plas said it was an ongoing problem the police face, with marriages, changes of surname or address contributing to the difficulty of tracking down licencees. He said these problems could be largely avoided by licencees ensuring police have an up-to-date address.
"It is actually an offence against the Arms Act 1983 if a licence holder fails to notify their local firearms officer or police of their new address.
"Every month in the Waikato we have a few people, half a dozen or so, that just don't respond."
He said failure to re-license could mean a uniformed officer turning up at the door to seize firearms.
"It's unusual that we need to go to that length because we are generally dealing with good law-abiding citizens, but we usually manage to sort it out before it comes to that.
"Sometimes there is dispute and sometimes they just hand them [firearms] over."
Renewals cost $126.50 - the same cost as applying for a new licence and follows a similar process, without the need to attend Mountain Safety Council firearms safety training.
"If a person allows their firearms licence to expire before renewing there is a higher fee to pay which is $241.50. So there's a financial benefit for renewing on time," Plas said.
As well as allowing Police to contact licencees, he said changes of address were also essential because a condition of the licence requires vetters to check security arrangements of new properties.
"What I've found is that sometimes a person will move and they will forget about sorting out the security of their firearms. Human nature being what it is they have got more important things to worry about moving house, but the guns sometimes tend to just get shoved under the bed or they prop it in a gun cabinet that is not bolted down.
"They might not have any bad intentions but it's a problem when a burglar comes along, has a look around the house and finds an unsecured firearm and suddenly you've got a person who has been negligent, and because of their negligence now enabled a criminal to get possession of a firearm. From there who knows where the gun goes."
He said police take a serious view against people whose failure to notify change of address and negligence has resulted in firearm theft, and if proven this will often result in revoking the licence.
There are about 24,000 licence holders in the Waikato.
"If a person is still holding firearms illegally they can surrender those guns to police at any time and they won't get in trouble for it. Or they can take any unwanted guns to a dealer because dealers have amnesty.
"We won't ask any questions if a dealer phones us up and says I've got a whole lot of guns here that have been surrendered."
