General question. What is the law/regulations on restrospective price increasing for gas/electricity suppliers?

I have just had a notification from Scottish Hydro about a price increase (very large) backdated to AUGUST. Surely they must notify you of the price of a service before you use it?

Any ideas?

Yes, they should really but then you should have notified them when you started to use the service.

They can backdate the increase by up to three months (or 65 working days). If you do not like the new prices you can switch to a different supplier. Tell them within 10 days of being informed that you reject their new prices and are switching. They then have to honour the original price.

Thanks ShiverKitchen - I feared as much.

MaxSteam - thanks for replying but not sure I understand what you mean by me informing them when I started to use the service - I've been a customer of theirs for 2 years. I may have misintereptted your answer, sorry.

Apologies, yes a misunderstanding here. I thought that you started using the service in August.