There is no general rule in England and Wales that the fence on the left is yours and the one on the right is your neighbour's. Whatever you were told when you moved in, the answer is in the documents, or it is nowhere.
What the title plan does and does not show
The title plan shows the land in the title edged in red on an Ordnance Survey base. Its boundaries are general boundaries: the red line shows roughly where the boundary runs, not the exact line. On its own the plan rarely says who must keep up a fence, wall or hedge: where a deed the register refers to marks a fencing duty with a T, HM Land Registry sometimes carry the mark onto the title plan, and otherwise nothing on it says. People buy the plan expecting it to settle the question, and by itself it seldom can.
Where the answer usually is
When the land was first sold off, the conveyance or transfer often made the buyer promise to put up and keep a fence on particular sides. On the plan attached to that deed those sides are usually marked with a T, by convention on the side of the line whose owner has the duty; an H (a T on both sides) usually means a shared one. The marks mean only what the deed's words say they mean, so the clause has to be read as well as the plan. The register tells you whether such a deed exists: an entry in the charges register saying a conveyance or transfer of a given date "contains covenants", with the note "copy filed", means HM Land Registry hold a copy and it can be sent to you.
So the order of work is: the title register first, to see which deeds it refers to; then the deed itself for the exact words and the plan with the T marks.
Three things a conveyancer would add
- A promise to put up and keep a fence is a positive covenant. Unlike a restriction on use, it does not pass automatically to later owners of the land; later deeds often carry it on through a chain of promises to indemnify, but not always.
- Where the deeds say nothing, no document decides. Neighbours usually go by who has maintained the fence, by agreement, or, for rural land, by old presumptions such as the hedge and ditch rule. A dispute about the line itself is a matter for a surveyor and, if it comes to it, a boundary agreement or a determined boundary application.
- A wall that stands astride the boundary, whether it divides two houses or two gardens (the Act calls the garden kind a "party fence wall"), comes under the Party Wall etc. Act 1996 when either owner wants to build on it or work on it; wooden fences and hedges do not. That is a separate question from who must keep the fence up.
What the check shows
The free check draws the plot and the building from open mapping; it says nothing about fences, because no public register does. The title register tells you whether a deed with a fencing covenant is referred to, and the register, plan and deeds together bring the deed itself, read into your certificate with the T marks explained.