Establishing property boundaries is important to know who owns what and what you are responsible for maintaining. Its particularly important in conveyancing as the buyer needs to be sure that they are really buying what the seller is selling. If the seller has the wrong boundary information for the property, the buyer could face a lengthy and expensive legal battle with their new neighbours and the seller may be liable for misrepresentation. It also effects where you can and can't build. If you build right up to the minimum distance from the boundary and then discover the boundary is just bit off, you could face serious problems.