Council chiefs revealed a banking glitch which saw thousands of council tax direct debits go wrong was rooted in last year's local government shake-up.
An investigation was launched after residents in the old South Northamptonshire District Council area had January's payments sent back to their accounts on Tuesday (January 4).
Cllr Malcolm Longley, West Northants' Cabinet Member for Finance, said: “We have investigated and discovered this was due to an administrative error on our part.
“This arose from the transfer to a new direct debit system from the three systems used by the previous tax collection authorities in West Northamptonshire, though this hasn’t impacted those living in the former Daventry and Northampton areas.
“The result was that some people will have noticed a payment being made and then immediately refunded to their accounts, and others will have had no payment taken at all."
Cllr Longley added that the council will make another attempt to take payments from bank accounts in the next few days.
He said: “We have now amended the details held on our system and will seek to request payments from people’s accounts later this week, so we would urge everyone to ensure they have sufficient funds available to cover this month’s council tax payment.
“We’ll do everything we can to contact those affected and alert them to this, and will use all other means at our disposal to ensure this message reaches the maximum number of people.
“We’re extremely sorry if this has caused an issue for anyone and we would urge them to contact us if this has led to any money issues or issues with your bank. Please rest assured that all of our processes will be reviewed to guard against this happening again in the future.”
Council advice for anyone facing financial or bank issues as a result of the problem should call 0300 126 7000 selecting options 2, 3, 2 and 1 to reach the dedicated customer service team for the south Northamptonshire area.