It says it is making the move in order to make its service more available to people struggling to cope with problem debt.
The CCCS freephone helpline will now be open between 9am and 3pm every Saturday and will be free to call from UK mobiles.
The move comes after the charity identified a clear demand for telephone advice at the weekend and a high proportion of clients (25%) calling from mobile phones.
In addition to its extended freephone helpline availability, CCCS will continue to offer free debt advice via its online debt counselling tool Debt Remedy which is available 24 hours a day.
CCCS director of external affairs, Delroy Corinaldi, said: “Around 370,000 people contacted us for help last year – a figure we expect to grow as an increasing number of financially vulnerable households fall into difficulty.
“It is crucial that these households are able to access free advice from a debt charity such as CCCS, instead of turning to profit-driven debt management companies who charge high fees that will only add to their debt burden.”