A paper-based vaccine "passport" could be SLOTXO available in Northern Ireland as early as 5 July, the Department of Health has said.
According to a statement, the initial specialised hard copy format will go live by 19 July at the latest.
The department says this will provide alignment with processes in the Republic of Ireland.
It has also been announced that 16 areas have been added to Northern Ireland's green list for travel.
Malta, the Balearic Islands - including Majorca and Ibiza - and Barbados are among the areas that will come on to the list from the early hours of Wednesday, 30 June, meaning people can travel to and from those places without having to quarantine as long as they provide proof of negative Covid-19 tests.
The department's vaccine passport announcement is aimed towards the goal of having an internationally-recognised form of proof that a person has had both vaccine doses.
It is expected the process of applying and receiving the hard copy certification will take 10 days.
The certificate will incorporate counterfeit protection measures, requiring a specialised printing process.
Dan West, the Department of Health's chief digital information officer, said the certificate would "complement the UK's existing traffic light system for international travel".
"While final decisions have still to be taken on how and when these vaccine certificates will be used, they are expected to make foreign travel easier for people who have had both doses.
"Governments and businesses may also decide to use them in other circumstances, such as access to events and activities.
"Such decisions have still to be made here in Northern Ireland and elsewhere."
A digital format is expected to be available by mid-August. It will support evidence of negative PCR tests, as an alternative to proof of vaccination.
Mr West said Northern Ireland's lack of a pre-existing health service app meant the department was "building our system from scratch".
No part of the health service in Northern Ireland, including GPs and vaccination centres, could provide proof of vaccine to the required standard for travel purposes.