The supplier said its customers who pay by direct debit and have more than £5 of credit on their account at the end of their yearly billing cycle will have the money returned.
SSE also said within the next 12 months it will introduce reviews into direct debit accounts twice a year to “provide reassurance” that customers’ payments are set at the right level.
Previously, customers had been able to request that any credit was refunded to them, whilst automatic refunds were made when an account had more than £100 of credit.
Tony Keeling, director of customer service at SSE, said the move was a “significant change to our direct debit policy that will help reassure customers they are getting a good deal”.
Last week, EDF Energy became the first of the six major suppliers to provide a full annual refund for any customers that are in credit, while British Gas and Eon will also refund customers who are in credit.
Vincent de Rivaz, chief executive of EDF Energy, said: “It’s the right thing to do and will give our customers peace of mind knowing they are not paying more than they need to.”