WhatsApp Ireland has been fined €225 million over breaches of data protection laws.
It's the largest ever fine issued by the Data Protection Commission and the second highest under GDPR.
The watchdog's investigation began in 2018 into the sharing of data with other Facebook companies.
WhatsApp is planning to appeal the decision.
Tech correspondent Jess Kelly says other European regulators disagreed with a proposed fine of up to €50 million.
"Because the Data Protection Commission was not able to reach a consensus, the case was then referred to the European Data Protection Board.
"In July of this year it was decided that the DPC must increase the size of the fine, which has resulted in a fine of €225m being passed on to WhatsApp Ireland."
