What Is an FMB Sketch and Why You Need It Before Buying a Plot in Tamil Nadu

A buyer in Vellore purchased a plot measuring 2,400 sq ft. He visited the site. The seller showed him the boundaries. Everything seemed right. Three years later, when he began construction, the neighbouring landowner produced an FMB sketch proving that a 200 sq ft strip of the land he'd been sold was actually part of the adjacent survey.

Two surveys. Two owners. One boundary dispute that took years to resolve.

The FMB sketch could have flagged this before the purchase was ever completed.

What Is an FMB Sketch?

FMB stands for Field Measurement Book. It is an official survey document maintained by the Tamil Nadu Survey Department for every survey subdivision in the state.

The FMB sketch is essentially a scaled map of a specific land parcel. It shows:

• The exact shape of the land

• Length and width of each boundary

• Area in square feet or cents

• Adjacent survey numbers (your neighbours' land)

• Roads or pathways touching the land

• Water courses, if any, running along or through the land

The FMB is prepared by licensed surveyors and is part of the official government land records maintained at the Taluk Survey Office and accessible through the Tamil Nadu e-Services portal.

Why Is the FMB Sketch So Important?

Property disputes in India are often boundary disputes. Who owns that strip of land between two properties? Does the road shown in the layout actually provide access? Does the extent in the sale deed match what's physically on the ground?

The FMB answers all of these questions — at least from a survey records perspective.

Without the FMB, you are relying on physical boundary marks on the ground (which can be moved or disputed) or on what the seller shows you during a site visit (which may not be accurate).

What to Check in an FMB Sketch

Survey Number and Subdivision

Confirm that the FMB sketch you're reviewing corresponds to the exact survey number and subdivision mentioned in the sale deed and Patta. A slight difference — survey 45/2A versus survey 45/2B — means you're looking at a completely different piece of land.

Extent

The area shown in the FMB should match the area in the Patta and the sale deed. Any discrepancy — even a small one — should be explained before you proceed.

Boundaries

Note each boundary: north, south, east, and west. The FMB will show what lies on each side — another survey number, a road, or a water course. Cross-check this with what you observe during a site visit.

If the FMB shows a road on one side but physically there's no road access to the plot, that's a problem. Either the road was encroached upon, or the access was part of an older layout that was never developed.

Shape and Measurement

Look at the shape of the plot. Is it regular? If the plot is irregular (narrower at the front than at the rear, or oddly shaped), you'll want to understand why before committing.

Adjacent Survey Numbers

The FMB shows who your neighbours are. Check if any adjacent survey number has an encumbrance or dispute — especially if your land shares a long boundary with it.

How to Get the FMB Sketch in Tamil Nadu

FMB sketches can be obtained through:

The Tamil Nadu e-Services portal (eservices.tn.gov.in) — Integrated into the unified land records view. You'll need the district, taluk, village, and survey number.

The Taluk Survey Office — For certified copies that may be needed for legal proceedings or loan applications.

The District Survey Office — For land parcels with complex or disputed boundaries.

Note that the online FMB may not always be fully updated, particularly for properties where recent subdivisions happened. In such cases, the certified copy from the Survey Office is more reliable.

FMB vs. Approved Layout Plan — What's the Difference?

In a plotted residential layout, you'll encounter two different types of boundary documents:

The FMB sketch covers the original agricultural survey parcel (before it was divided into residential plots).

The DTCP or CMDA approved layout plan covers the residential plots that were created by subdividing the original survey land.

Both are important. The FMB tells you about the parent survey. The layout plan tells you about your specific residential plot. If your residential plot was carved out of a survey number, the layout plan is what defines your specific plot's shape and size.

When the FMB Raises Questions

Sometimes the FMB sketch raises issues that require further investigation:

• The extent in the FMB is less than what's being sold — This could mean the seller is selling more than they own, or that there's a discrepancy between old survey records and a more recent subdivision.

• A government notation on the FMB — Some FMB sketches have notations indicating that part of the land is classified as tank bed, water course, or government poramboke. These portions cannot be sold.

• The boundaries don't match the site — If the boundaries shown in the FMB don't correspond to what you see on the ground, there may be an encroachment or an error in the records.

LandCheck includes FMB sketch verification as part of its comprehensive property reports. Trained professionals compare the FMB with the sale deed, Patta, and physical site information to flag any inconsistencies before you proceed.

→ Avoid boundary disputes. Verify your property's FMB sketch with a LandCheck report at landcheck.in.