Brussels will put forward a draft law this month to create so-called vaccine passports, European Commission (EC) President Ursula von der Leyen has announced.
It will be called a Digital Green Pass and include details such as whether the person has been vaccinated, as well as previous COVID-19 test results and medical statements.
The draft law will be followed by at least three months of technical work.
This means the pass could be introduced, at the earliest, in July.
"The Digital Green Pass should facilitate Europeans‘ lives," said von der Leyen. "The aim is to gradually enable them to move safely in the European Union or abroad - for work or tourism."
Health policy is a competence of EU countries and the European Commission has little say in this policy area. However, the vaccine passport will be based on the freedom of movement within EU territory, a field where Brussels has greater executive and legislative powers.
"We're working towards facilitating safe and free movement in the European Union, not restricting it," an EC spokesperson said.
Eric Mamer, the chief spokesman of the EC, was unable to explain whether non-EU citizens could obtain the pass.
In order to move ahead, the EC will need member states to act quickly, particularly in regard to "IT systems and interconnections", he added.
The idea of introducing vaccine passports has been touted since the beginning of the inoculation campaigns.
Last week, German Chancellor Angela Merkel, speaking to media after the EU leaders' video-conference, said the certificates could be ready by summer.
"Everyone agreed that we need a digital vaccination certificate," Merkel told reporters.
Tourism-reliant countries like Greece and Spain have stepped up their lobbying in recent weeks in a bid to salvage the 2021 summer season.
Greece has already issued digital vaccination certificates, becoming one of the first EU governments to do so.
Nevertheless, disagreements among member states around the idea and scope of these passports are expected to persist. Countries less dependent on tourism don't share the south's hurry and are more concerned about the potentially discriminatory side effects of the measure.
Following von der Leyen's announcement on Monday, Sophie Wilmès, the Belgian foreign affairs minister and former prime minister, took to Twitter to both welcome the proposal and criticise it.
"In Mrs Von der Leyen's proposal, the notion of a "pass" is confusing in relation to the objective that this certificate should pursue," Wilmès wrote.
"For Belgium, there is no question of linking vaccination to the freedom of movement around Europe. Respect for the principle of non-discrimination is more fundamental than ever since vaccination is not compulsory and access to the vaccine is not yet generalised."