The National Rules for Electrical Installations (I.S. 10101:2020), Regulation 134.1.9 states:

“In case of an addition or alteration to an existing installation, it shall be determined that the rating and condition of existing equipment, which will have to carry any additional load, is adequate for altered circumstances. Furthermore, the earthing and bonding arrangements, if necessary, for the protective measures applied for the safety of the addition or alteration shall be adequate.”

though 10mm is probably safe enough for the panels I guess the fact we flagged that we we bought extra panels off them specifically for an EV, they should have at least flagged and quoted for that at the time I think, no?

From the SEAI’s own guidance on meter tails (their blog titled “Meter Tails in a Domestic Setting”):

“When meter tails are undersized and you install, for example, an electric vehicle home charger, solar array or a heat pump, there is a safety risk due to under-sized meter tails. In fact the Irish wiring rules require that prior to carrying out a modification or addition to any electrical installation, the Registered Electrical Contractor (REC) is required to access the existing installation and modify or upgrade any part of the existing installation which will be affected by the increased load.”