What "approved premises" actually means
Every venue on this site is an approved premises. It is a specific legal status rather than a description, and knowing what it does and does not cover explains most of what is confusing about looking for a wedding venue.
It is the building that is approved, not the wedding
A council approves a place to host civil marriages and civil partnerships. The approval attaches to the room and the premises — it says this is somewhere a ceremony may lawfully happen. It says nothing about whether the venue wants to host weddings, whether it is any good at it, or whether it is free on your date. A working men's club and a stately home hold the same status.
That is why a list like this one can be complete in a way a wedding directory cannot. There is a definitive answer to "is this place approved", and it is published. There is no definitive answer to "is this place nice".
What is not on the list
Churches, chapels, mosques, synagogues and other religious buildings. Religious premises are registered under a separate system and do not appear here. If you are marrying in a place of worship, this list is not the one you need.
Scotland and Northern Ireland. They license the celebrant — the person conducting the ceremony — rather than the building, so there is no equivalent list to publish. This is why the site stops at the Welsh and Scottish border rather than out of any preference.
Anywhere not yet approved. A venue can apply at any time, and councils grant approvals between one edition of the list and the next.
How many there are
7,163 premises across 317 council areas in England and Wales, of which 594 are in Wales. The typical council area has 16 of them. The full counts, and how they are spread, are on the numbers page.