Parish Boundaries
Traditionally, Church of England churches, "Parish Churches", minister to those who live within their parish boundaries - and every home in England is part of a Church of England Parish.
More recently, the law has also allowed those with a specific "connection" to get married in a particular church.
The map will show you if if you live inside the parish.
St. Thomas' Parish Boundaries
These are St. Thomas' Parish Boundaries:

Alternatively, you can enter your postcode at "A Church Near You" to see which parish you live in: