Several charities are among the more than 350 employers that have been named by the government for failing to pay the minimum wage.
The biggest voluntary sector offender is the social care charity Community Integrated Care, which according to the Department for Business, Energy & Industrial Strategy underpaid 69 workers a total of £19,775.
The charity said the mistake came because it had been unclear on the legal position relating to care staff travelling to appointments, but this had now been rectified.
Community Integrated Care is ninth on the latest list of offenders published by the government, ordered by amount owed.
The retailer Debenhams is the worst offender, having failed to pay £134,894 to 11,858 staff.
Andrew Sleigh, chief financial officer at Community Integrated Care, said the matter had been resolved.
"Until recently, there was not a clear legal position on paying staff providing domiciliary care for their time spent travelling to appointments," he said. "And, indeed, the restricted funding from our local authorities in many cases did not support this.
"When recent case law meant that travel time should be factored into people’s pay, we acted swiftly to resolve this. We took proactive steps to contact all affected employees and fully reimburse them for the amount that they were owed.
"This is a matter that has affected many organisations in our sector and we would never intentionally under-value our colleagues. We would like to offer our sincere apologies to all staff affected."
Both Crossroads Caring Scotland and Age Concern Newcastle said the failure to pay the minimum wage also related to travel time.
CCS said: "The incident referred to occurred more than 16 months ago and was the results of an oversight relating to travel time. Forty of our more than 650 staff were affected.
"As soon as the breach was identified, we worked closely with HM Revenue & Customs to ensure that our workers received the full back pay that they were entitled to and to ensure our compliance with this complex legislation in the future.
"As a result, we have put in place processes to ensure that such a breach cannot occur again. All of our support workers are now paid the Scottish Living Wage of £8.25, which will increase to £8.45 in April."
Age UK Newcastle said: "Following a visit from HMRC in October 2014, Age UK Newcastle discovered an underpayment of the national minimum wage to a member of staff relating to travel time.
"We took action to rectify the situation in January 2015 and a thorough review and correction of underpayment was undertaken."