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.

JCG Year 7 Choir learn and perform wartime song
Gas bills to go up by 5% in December
Second memorial plaque vandalised at Millennium Park
'They got our hopes up': Young islanders disappointed as Fort Regent plans stall
Electricity prices in Jersey to rise by 2.5%
Minister says he has been 'slated' and his family taken 'abusive' phone-calls over economic growth comments
GALLERY: First-look at Jersey Airport's revamped Departures Lounge
Take a look at the Channel Islands' new all-weather lifeboat