Good morning Matthew,
We live in a block of flats, you as the first line of address for flat C, the flat is not known by flat C anymore.
The bill should show the first line of address as "First Floor Flat," which is the address showing every bill, council tax, and tenancy agreement.
I'm not sure why you're using this first line of address or how to explain it. This may be an error.
Can you please assist me with this issue?
Regards