Less than a quarter of schools are using a $34-million Education Ministry system for sharing student information.

The ministry said 551 of the 2536 schools in New Zealand were using the cloud-based system called Te Rito, but a further 503 were signed up and waiting to be connected.

The programme began in 2019, but was paused in 2021 because of security weaknesses in the various student management systems (SMS) schools used to record student details.

Roll-out resumed in January 2023 but this year's Budget trimmed $6m from the programme's original $40m budget to spend elsewhere.

The ministry said Te Rito connected with schools' student management systems (SMS) only if they passed Safer Technologies for Schools (ST4S) accreditation, which checked that their security and privacy settings were appropriate.

"Te Rito will only share data with an SMS that has met a minimum-security standard of ST4S," it said.

"We are proactively ensuring new security vulnerabilities are mitigated as an ongoing process that all SMS vendors need to manage."

The ministry's Te Rito website said the four main SMS systems used by schools could connect to Te Rito.

It said the system allowed schools to share learners' records including NCEA achievement, health and language information, and any ministry-funded support for which they might be eligible.

However, the ministry said it would not be used for a new learning support case management system for children with disabilities and extra learning needs.

"Te Rito was not designed as a learning support case management system. Te Rito is a data exchange platform designed to securely move data between schools and from schools to the Ministry and vice versa. It does not have case management functions," it said.

The ministry said it would develop the register itself using technology belonging to Salesforce, a platform the ministry used for functions including emergency management notifications, curriculum support services and school transport assistance.

"The ministry is developing a Learning Support Case Management system using existing Salesforce technology and an in-house project team. While the Ministry may draw on specialist Salesforce technical expertise as needed, Salesforce is not responsible for developing or delivering the system," it said.

The ministry would not say how much it spent on Salesforce licences for schools.

"The spend is commercially sensitive. Because Salesforce is used for a range of Ministry services it wouldn't be accurate to provide a figure for the number of schools covered by these licences," it said.

However, the ministry said 2490 schools had accessed Salesforce in the past 12 months.