Thousands of pounds of council tax bills have not been collected because of a blunder that went unnoticed for almost a year.

Brighton and Hove City Council failed to collect at least £10,000 after staff made mistakes when inputting the details of residents' direct debit instructions into their computer system.

Banks have been unable to honour the council's monthly requests for payment because details such as account numbers or sort codes were wrong.

The blunder came to light ten months after the data was typed in when one of the residents realised his monthly bills had not been taken out of his bank account.

This triggered a check by officers, who scrutinised their computer records and discovered a further 27 residents had not been paying council tax.

This was despite their best efforts in following the council's instructions to set up a direct debit.

The unwitting debtors have been sent a letter apologising for the mistake and demanding payment for the last financial year's uncollected bills.

Some families are outraged they could have to pay almost double their monthly bills from April, to pay off debts amassed through no fault of their own.

Kate and Simon Copeland, of Rutland Gardens, Hove, were shocked to discover they had not paid any council tax since they moved into their property in April last year.

After sending the council their direct debit instruction, they assumed the money was being transferred each month and believed they had no reason to scrutinise their bank statements to check the bills were being paid.

They assumed in good faith the council was collecting the money direct from their bank.

The couple, who are both journalists, will have to pay £1,062 in unpaid bills on top of next year's demand of £1,332.69 for their Band F property.

Mrs Copeland said: "They failed to take our money and failed to tell us about it for a year.

"The bottom line is that a lot of people are going to have to pay double this year.

"Why did it take them so long to tell us? How did they fail to notice all this money was going uncollected?

"When my husband called the council, they were more or less accusing him, saying, 'why didn't you look at your bank statements?' but once a direct debit is set up you just assume the money is being taken out.

"We have just received our bill for this year's council tax.

"I have just had a baby and now have three children so this is the last thing we need. It's not like we have put the money aside."

A council spokeswoman said mistakes were either made by council staff as they keyed in details from direct debit instructions or by taxpayers themselves when filling in the forms.

She admitted the errors were not checked until ten months later.

However, she said the onus was on the taxpayers to check the money was being transferred.

She said: "To put this into context, 44,000 people pay by direct debit. There are 22,000 new direct debits annually and these have to be inputted manually.

"There was an error in 28, either a figure was transferred incorrectly or it could be on the taxpayers' side.

"The council contacted the 28 people in February. We wrote to them apologising for the error and asked them to get in touch with us to make arrangements.

"In law, there is a presumption the debtor will seek out his or her creditors. One person did this and they made arrangements to pay over a period of time."

She admitted people would question why it took the council a year to notice the error, adding: "You could say it's amazing that 28 people took so long to notice."

Some residents have not been paying council tax for ten months while others, who arranged direct debits later in the year, may have only been building up debts for two months.

Council officers said they could not give a breakdown of figures, detailing how much money was owed by each the 28 residents, but said the £10,000 debt was an "estimated guess".