What is an FMB sketch?
last updated 2026-07-21
An FMB — Field Measurement Book — sketch is the Tamil Nadu survey department's scaled drawing of a land parcel, showing its actual shape, measurements and boundaries on all sides. Unlike patta or the EC, it is about the physical extent of the land, and it is how you check that the plot matches what is being sold.
What the FMB is
The Field Measurement Book is a register maintained by the Tamil Nadu survey and settlement department holding ground measurements of every land parcel. The FMB sketch is the scaled map drawn from those measurements — typically at 1:1000 or 1:2000 — showing the parcel's shape, orientation and boundary lines on each side.
FMB vs EC vs patta — they answer different questions
| Record | Answers |
|---|---|
| Patta / Chitta | Who owns it, and what class of land it is. |
| Encumbrance certificate | What registered transactions and charges sit on it. |
| FMB sketch | Where its boundaries are and what shape and extent it actually has. |
Why it matters before buying
The FMB is how you check that the boundaries and extent on paper match the ground — that the plot is the shape and size the sale describes, and that it is not encroached or mismatched with a neighbouring survey number. For a land or plot purchase at auction, where you are buying as-is-where-is and the notice states an extent, comparing that extent to the FMB is a direct sanity check on what you are paying for.
How to read an FMB sketch — what to check
You don't need to be a surveyor to get value from an FMB. Run through four things:
- Survey / sub-division number — it must match the number on the patta and the sale notice. A mismatch means you may be looking at the wrong parcel.
- Shape and boundaries — the four sides and the parcel's shape should match what's on the ground and what the seller describes.
- Extent — the measured area should tally with the extent stated in the notice once you convert to a common unit. A gap here is a red flag.
- Neighbours and encroachment — adjoining survey numbers are marked; check the plot isn't overlapping or encroached.
How to get an FMB sketch
The FMB sketch is available through the Tamil Nadu land-records e-Services, keyed to the district, taluk, village and survey number. Confirm the current access route and any fee on the official portal — see the sources below.
Frequently asked questions
What is an FMB sketch?
A Field Measurement Book (FMB) sketch is the Tamil Nadu survey department's scaled drawing of a land parcel, showing its actual shape, measurements and boundaries. It reflects the physical layout of the land, not its ownership.
How do I read an FMB sketch?
Check four things: the survey/sub-division number matches the patta and notice; the shape and boundaries match the ground; the measured extent tallies with the stated extent; and the plot isn't encroaching on or overlapping neighbouring survey numbers.
How is the FMB different from the encumbrance certificate?
The FMB shows the parcel's measurements and boundaries; the EC shows its registered transaction and charge history. One is about the physical land, the other about its legal record — you check both.
Why check the FMB before buying at auction?
Because an as-is-where-is sale states an extent without warranty. Comparing that extent and the boundaries to the FMB confirms the plot is the shape and size described and isn't encroached or mismatched.
Related terms
Sources
Rates, fees and procedures change — confirm the current position on the official portals below before you act.