I restored my iPhone but it still says I can't back it up?

I restored and a message still comes up saying not enough storage to back up to iCloud, I back up through my phone but there's only photos on my iPhone, I'm on the 5GB storage plan?

It sounds like you have somehow gone over 5gb storage. Do you have a lot of photo?
Also is your iPhone the only thing backed up to iCloud or do you have Mac, iPod, iPad ect all backed up. If they're all on the same apple ID then they are all taking up space on the cloud.
I've got two apple IDs on different email address. One for iCloud and one for iTunes (apps ect) This way I get 5GB on each