Thousands of households have had their electricity accounts transferred to new suppliers in error or without their consent, as complaints over problems with power companies have hit all-time highs.

Complaints about electricity companies rose by more than 50 per cent to 29,924 over the past 12 months, according to the Energy and Water Ombudsman.

Complaints have doubled over delays to bills being received or not received at all, along with disputes over site ownership.

As well, households and businesses who had accounts transferred in error surged by 90 per cent, while accounts transferred without consent rose 84 per cent.

In one case, a visitor to a household agreed to change supplier when talking to a door-to-door salesman or a telemarketer, but not the account holder.