More than 1.3 million emails and letters containing the EU Digital Covid Certificate have been issued to people who have been fully vaccinated.
Minister of State for eGovernment Ossian Smyth told the Oireachtas Committee on Transport and Communications that 984,000 emails and 350,000 letters have been sent.
The Government aims to have 1.8 million issued by Monday 19 July.
Of the emails sent, 7,500 have "bounced", which is failure to send rate of 0.7%.
Minister Smyth told Fine Gael's Joe Carey that "when you have a database of emails and more than 99% of them are delivering, that's an incredibly high-quality data set".
He added that the 7,500 people who did not receive their email will likely have to call the dedicated call centre, which will be up and running on 19 July.
Many of the letters are being posted by Revenue, which aims to send between 50,000-70,000 letters per day, with a ramping up this weekend, the committee heard.
At least 90% of the postal certificates should be sent by Monday.
From the middle of this week another round of EU Digital Covid Certificates will be sent out to those who were not included in the initial round, because they were vaccinated within the past few days.
Fianna Fáil TD Cathal Crowe asked how quickly somebody could expect to receive their cert after receiving their final vaccine dose.
Government Chief Information Officer Barry Lowry said GPs and pharmacies upload data to the COVAX system on a daily basis and that data is then transferred by the Health Service Executive to a "data lake".
The HSE verifies the data and finally a "batch" is created.
Once a batch is created, the cert can be sent out to people within 1-2 days or 3-4 days, depending on whether it is sent by email or post, he said.
No quarantine for fully vaccinated arrivals
The committee also heard that new travel arrangements, coming into force from 19 July, will allow all non-EU arrivals into Ireland avoid quarantine if they are fully vaccinated or have received a negative PCR test.
However, mandatory hotel quarantine will still be in operation for those arriving from the list of designated countries.
Mr Smyth said he understood that only vaccines approved by the European Medicines Agency would be accepted under the arrangement.
He added that it has yet to be decided if fully vaccinated tourists would be allowed to avail of indoor dining.