Hello, I moved recently to the UK. The house I rented was using bulb and I didn’t change it. I received a letter for my bill, but don’t know where to pay it. I went to the post office, but they told me there should be a barcode, which my letter didn’t have. I am afraid, that I would have to pay fine, for not paying on time. I have set my direct debit, but still don’t know how the system works.