CRG, who operate the plazas on several motorways, including the Portlaoise, Waterford and Limerick Tunnel tolls say they've been informed by Eflow that from the end of August, the tags will no longer work.
The tag system has been in operation for over a dozen years, with almost 50% of drivers using them. Eflow is one of the main suppliers of the tags.
Lorcan Wood of CRG says the dispute centres around payment contracts.
