DD, 2, had an outpatients hospital appointment in the summer for suspected asthma. Saw the consultant, we where packed off with a prescription, all fine.
We're in the UK, it was an NHS appointment based on a GP referral.
Today, I opened an invoice from the hospital for £330! 
It's just an invoice, no explanation of why we're being charged.
I can ring in the morning and ask but wondered if anyone knew why this might have happened?