Almost 40,000 people are still waiting for a booster vaccine certificate after getting the extra jab.
Figures in the Irish Examiner show administrative errors have held back a small number of the over- 2.7 million requests received so far.
The Department says these errors could include a wrong email address being provided,
About 2.1 million people received an updated digital certificate and around 570,000 requested a paper document by post.
