Introduction
In Tamil Nadu, every property is tied to a survey number in the revenue records. Alongside, the Field Measurement Book (FMB) sketch provides exact boundaries and subdivision details. But when patta entries don’t match the FMB, disputes arise — leading to confusion, encroachment, and even litigation.
This article explains how to handle survey number mismatches, verify FMB boundaries, and resolve disputes before they become costly.
What is a Survey Number?
- A unique identifier for every land parcel in a village or town.
- Subdivision numbers are added when land is divided.
- Forms the basis for patta, chitta, A-Register, and EC records.
What is the Field Measurement Book (FMB)?
- A sketch maintained by the Survey Department.
- Contains:
- Boundary lines of each survey number
- Subdivision extents
- Neighboring survey references
- Serves as the official record in case of boundary disputes.
Why Do Disputes Happen?
- Patta vs. FMB mismatch – The written record (patta) and the actual measurement map (FMB) don’t match each other — and that creates disputes about the true size or boundary of the land.
- Subdivision errors – New survey numbers incorrectly recorded.
- Encroachment – Adjoining landowners use vague boundaries to occupy extra space.
- Digitisation mistakes – During Updating of Registry , details were wrongly entered.
How to Verify Survey Numbers & FMB
- Check Patta & Chitta – Obtain latest revenue records.
- Get the FMB sketch – Request at e-Sevai/Taluk office.
- Compare boundaries – Match with sale deed descriptions.
- Apply for Resurvey – If mismatch exists, file a petition with the Tahsildar.
- Escalate if needed – Approach the Revenue Divisional Officer (RDO) or civil court for unresolved disputes.
Regulations & Local Rules
- Governed by the Tamil Nadu Survey & Boundaries Act, 1923.
- FMB sketches maintained by the Survey Department are considered final.
- Only civil courts can settle disputes if ownership overlaps with boundaries.
Common Mistakes & How to Avoid Them
- Buying land without checking FMB.
- Assuming patta alone is sufficient proof.
- Ignoring subdivision mismatches before registration.
Practical Tips
- Verify survey numbers using the Survey Number Finder Tool.
- Always cross-check Patta, FMB, and Encumbrance Certificate together.
- For agricultural land, confirm subdivision boundaries match actual ground extent.
- Use resurvey requests to correct records before sale.
Relevant Verified.RealEstate Services & Tools
- ✅ Land Use & Survey Tools – Check zoning and classification by survey number.
- ✅ Patta & FMB Verification Service – Ensure records are accurate before buying or selling.
Conclusion
Survey numbers and FMB sketches are the backbone of property boundaries in Tamil Nadu. But mismatches can lead to disputes that drag on for years. By cross-verifying patta and FMB before any transaction, and applying for resurvey where needed, buyers and owners can secure their property rights and avoid costly mistakes.