In May they decided it was about time they put the bill in their own names.
Simister said he called Trustpower and made the change.
Little did he know that creating a new account at that time of year would mean the account would not be old enough to be eligible for this year's payout, which in previous years had been about $550.
TECT general manager Wayne Werder said to be eligible for the cheque, accounts have to be continuously active from April 1 to September 30 in the same name, with a 30-day grace period allowed for people who move house.
Simister said he realised something was wrong when his annual cheque did not arrive come December. He was seething when he found out why, and how easily it could have been avoided.
He said if Trustpower had mentioned that rule when he called, he simply would have waited until a date outside the eligibility period to make the change because it was not urgent.
A Trustpower spokesperson said there was no mention of TECT cheque eligibility by either Simister or the customer service agent during the call.
The cheques were facilitated and eligibility criteria set by TECT.
"As TECT's policy is clear there was no reason for us to raise the question of lost eligibility.
"We recognise this is an unusual situation and while there is a clear family link they are clearly two different account holders."
The spokesperson said that given the company's long relationship with the family, it had offered to credit to his electricity account.
TECT cheques
• $28 million dividend distributed in 2018
• 55,293 eligible Trustpower customers received a share
• Cheque paid to person/organisation named on the Trustpower account
• The eligibility period is April 1 to September 30
• Accounts must be continuously active in that period
• Accounts must remain in the same name in that period
• TECT cheques turned 25 in December.
Source: Tauranga Energy Consumer Trust