Digital Covid-19 vaccine certificates now only show a QR code for the latest dose.
The government says it's to simplify the process for islanders using their certificates for travel reasons.
Up to five doses are now available for islanders to generate. Previously, only three were available.
Certificates downloaded into a Google or Apple wallet will now expire after six months.
PDF certificates sent by email through the Coronavirus Helpline or the Covid Status Certificate email function will still expire after 30 days.
The Yoti app and a OneGov account are needed to self-generate a certificate.
Several countries require evidence of a person's vaccination record or a negative Covid-19 test result or recovery before allowing entry.
It expires after 180 days and can't be extended.

Jersey Airport to see 20,000 passengers in the run up to Christmas
Both winning CI Christmas Lottery Tickets sold in Jersey
Jersey churches host free Christmas events in the Royal Square
Support service set up for carers of people with mental illness
New Jersey Opera House CEO appointed
Aurigny to fly between Guernsey and Jersey next year
Woman still in hospital following Les Quennevais crash
Former CI Co-op boss awarded more than £3m