Another 30,000 calls were made to the Digital Covid cert helpline yesterday - but fewer than 2,000 were answered.
Just 7% of travellers have been able to get through since the start of the week.
The Department of Health says many callers don't have urgent questions - which is adding to the wait times.
The government has apologised to people who've had a bad experience with the Digital Covid cert helpline.
Travellers are still reporting long delays trying to get through as the demand's been higher than expected.
The Tanaiste has apologised over the issues - and says staffing on the helpline is being increased to 90.
📢The Digital COVID Certificate helpline is experiencing a high level of demand.
✈️If your departure date is more than 10 days away consider contacting the helpline at a less busy time
📃Please have the relevant information at hand pic.twitter.com/JdGaXVJcHK
— MerrionStreet.ie (@merrionstreet) July 20, 2021
The government is also hoping to reduce the time it takes to get your cert after your 2nd vaccine from 72 hours to 48 hours.
And the Department of Justice says border agents are accepting HSE cards as proof of vaccination.
It also hasn't come across any cases of fraudulent Digital Covid Certs being presented at Dublin Airport to date.