Is it legal to add a non direct debit fee to a utility bill?

Two years ago I stopped paying one of my utility bills by direct debit; instead I pay by cash. My supplier added a non direct debit charge to my bill each month. I thought nothing of this until I told that this wasn't legal.

I'm not sure how true this is. Could somebody please clarify?

The short answer to your question is that your source is incorrect and there's nothing stopping these types of surcharges, once the customer is properly informed and the surcharge is clearly displayed.

Section 48 of the would have prohibited these types of sucharges, except that Section 48 was exempted in the Act's . According to a statement in the Dáil by Micheál Martin (the relevant Minister at the time), this section and one other would have been contrary to EU law so they weren't brought in force.

a good way to look at it is the fact your gaining a discount by goin dd, same as paying your car tax in full....