If a seller has shown you a plot and you want to check it against the official record, the FMB (Field Measurement Book) sketch is the document that shows the surveyed shape of the land. This is for anyone about to compare a plot on the ground to its paper record. By the end you’ll know what the sketch shows, how to walk it against the deed, and when the mismatch is serious enough to call in a surveyor.
What is an FMB sketch?
An FMB sketch is the Tamil Nadu survey department’s measured diagram of a single survey number, drawn to scale from field measurements rather than copied from a legal document. FMB stands for Field Measurement Book, the register the department keeps for each village. The sketch is a technical record of shape and extent, not a record of ownership — ownership is established by the registered chain of deeds, not by this sketch or by the patta. You can request an FMB sketch for a survey number through the Tamil Nadu e-Services portal (eservices.tn.gov.in), the same portal used for patta chitta, A-Register extracts and TSLR records.
What does the sketch show?
The FMB sketch shows the outer boundary of the survey number, the measurement along each boundary line, and the survey numbers of every parcel that touches it on each side. Where the number has been split over time, it also shows the subdivision lines, with each subdivision marked separately and its own extent. A north arrow orients the drawing so you can tell which boundary is which. None of this is a legal opinion — it’s a geometric plan, the same one the surveyor used when the number was last measured or subdivided.
- Outer boundary lines with their measured lengths
- Survey numbers of adjoining parcels on every side
- Subdivision lines and subdivision numbers, if the parcel was split
- North orientation, so boundaries can be matched to compass directions
How do you match the sketch to your deed?
You match an FMB sketch to your deed by comparing the survey number and subdivision number written in the sketch to the schedule of property in your sale deed, then checking that the boundary description in the deed — usually named as the survey numbers to the east, west, north and south — agrees with what the sketch shows on each side. If the deed names a different neighbouring survey number than the sketch does, or describes an extent that doesn’t match the subdivision’s recorded area, that’s worth resolving before you go further, not after.
How do you walk the boundary?
Walking the boundary means standing at each corner the FMB sketch marks and confirming a matching feature exists on the ground — a boundary stone, a fence, a drain, a wall, or the visible edge of the neighbouring plot — in roughly the position and distance the sketch’s measurements describe. Bring a printed copy of the sketch and the deed schedule with you, not just a photo on your phone, so you can trace each line as you stand on it. Ask the seller or their representative to walk it with you and point out where each corner falls.
- Carry the printed FMB sketch and the deed schedule together
- Locate each corner point and check the boundary feature at it
- Confirm the subdivision shown matches the extent the seller is offering
- Note any mismatch in writing before proceeding with the purchase
What can the sketch settle for you?
An FMB sketch can settle whether the plot you were physically shown corresponds to the record geometry — the same survey number, the same subdivision, and boundaries whose measurements and adjoining survey numbers line up with what you found on the ground. That’s a real and useful check: it catches cases where a seller points to a larger or differently shaped plot than the one actually recorded under that number. What it settles is shape and identity, not entitlement.
What can’t the sketch prove?
An FMB sketch cannot prove who owns the land — that question is answered by the registered chain of deeds, not by the patta or by a survey diagram — and it cannot certify that there is no encroachment on the ground. A sketch is drawn from the last time the department measured the parcel; it does not update itself when a neighbour’s wall creeps over the line afterward. Confirming actual on-ground boundaries against the recorded ones needs a licensed surveyor with modern measuring instruments, not a visual comparison against a printed sketch.
When do you need a formal survey?
Ask for a formal government survey when the FMB sketch and the ground disagree in a way a visual check can’t settle — a boundary stone that’s missing, a neighbour’s construction that appears to sit over the line, or an on-ground extent that looks noticeably smaller than the subdivision’s recorded hectares and ares. This is typically arranged through the taluk survey office or a licensed surveyor, and the process and any charges vary, so check current requirements with that office directly. Where the mismatch is significant or the seller disputes it, take qualified legal or survey advice before you commit funds.
Where does the FMB sketch fit?
The FMB sketch is one record among several worth checking before you commit to a purchase — alongside the patta chitta, the A-Register extract and the encumbrance certificate — and it’s the one that speaks specifically to shape and boundaries rather than ownership or transaction history. viewpatta fetches the FMB sketch for a survey number from the Tamil Nadu e-Services portal on your behalf; you only pay when a complete record is actually found, since an empty result is a zero-rupee outcome, not a failed charge.
