AT Hop card Photo: RNZ / Cole Eastham-Farrelly
Auckland Transport is on track to ensure its systems are ready for half price fares for under 25s from 1 July.
The government announced the initiative in the Budget on 18 May, including that children aged between five and 12 will travel for free.
Earlier this month, Auckland Transport metro optimisation manager Richard Harrison said the new concessions required "technical changes" to its existing HOP system and it did not know whether it was possible given the complexity of changes needed.
But the work was complete, ready to roll out on 1 July.
"I'm really proud of the team. They've worked hard over the last five weeks to make this happen," he said.
"Anyone who works with IT might understand that this is a really big change. There are hundreds of thousands of HOP records that we need to carefully make changes to.
"Think of it like a software update that we will publish on Tuesday evening. All of our vehicles and HOP equipment will download that update and they'll be updating from Tuesday through to Friday. Then at one minute past midnight between Friday and Saturday that update will automatically take effect."
Aucklanders will need to register their AT HOP card with their date of birth so the appropriate fare can be applied.
Half price fares end for customers aged 25 and over on 30 June.