There were some 145,000 students thought to need devices or connections before online school started up.
But with too few modems and laptops available in New Zealand - and a worldwide scramble to provide them to students as schools closed down across the globe - the Ministry of Education warned it would have to ration the devices, sending them out in "tranches over time" to ensure the most disadvantaged students received them first.
This would "avoid perpetuating or increasing existing inequities in education".
There were thought to be about 7000 devices available within New Zealand according to an early April briefing. These would be "supplemented with offshore supply" with the first shipment to arrive four weeks later.
The ministry said it planned to prioritise students doing NCEA level 2, followed by level 3 and then level 1 before working through younger age groups, always with a focus on disadvantage, including ethnicity and socioeconomic.
"This reflects the relative importance of the different levels to learner pathways into work and tertiary study," the advice said.
It was surveying schools in the first week of April to understand more about which students fit those categories.
Once more information was available about students' needs it could take a more "nuanced" approach, including looking at which schools could fully deliver teaching online, and whether students were sharing devices with other siblings or adults at home.
The ministry was also concerned that distributing laptops to students based on their school's decile would risk some more disadvantaged students missing out if they happened to go to richer schools.
• Covid19.govt.nz: The Government's official Covid-19 advisory website
The Herald understands some low-decile schools have still not received the promised devices, with potentially just a week to go before schools reopen completely.
The ministry also advised that due to uncertainty over the impact of Covid-19 it needed to sign a contract with TVNZ to provide a distance learning channel for at least three months, through to June 30, which would require extra funding.