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OC vs CC: Why the Occupancy Certificate Matters Before You Move In

A Commencement Certificate (CC) lets a builder start construction; an Occupancy Certificate (OC) says the finished building can be lived in. Here's what each means, what goes wrong without an OC, and what to ask for.

By Elegant Home Advisors · Updated 2026-10-16

Two certificates from the planning authority bracket every new building: one before construction starts and one after it ends. In Navi Mumbai the planning authority may be CIDCO, the Navi Mumbai Municipal Corporation (NMMC), the Panvel Municipal Corporation (PMC) or, around the new airport, NAINA, depending on where the project is.

Commencement Certificate (CC)

The CC is the permission to start construction according to the sanctioned building plans. It is often issued in stages, for example up to the plinth first and then for further floors. A project cannot be registered with MahaRERA without its approvals, and the CC is one of the documents a developer uploads.

What it tells you: the plans were approved and the builder may build up to the floors covered by the CC. If you are buying on the 30th floor, check that the CC covers the 30th floor.

Occupancy Certificate (OC)

The OC is issued after construction, when the authority is satisfied that the building has been built according to the sanctioned plans and is fit to live in (fire safety, water, drainage, lifts and so on). It is the document that makes it legal to occupy the flat.

Part OC

Large projects often get a part OC for some wings, towers or floors while the rest is still being built. Always check that the OC covers your tower and your floor, not just "the project".

What can go wrong without an OC

  • Moving in may not be legal. The authority can treat occupation without an OC as unauthorised.
  • Utilities: permanent water and electricity connections can be delayed, or charged at higher temporary rates.
  • Home loans and resale: many banks will not lend against a flat without an OC, which makes it harder to sell later.
  • Society and conveyance: forming the housing society and getting the land conveyed to it is harder.
  • Property tax may be assessed with penalties.

Completion certificate

Some authorities issue a building completion certificate along with or before the OC. For a buyer, the OC is the one that matters most.

What to ask your builder for

  1. A copy of the CC covering your floor, before you book.
  2. For a ready flat, a copy of the OC (or part OC) covering your tower and floor, before you pay the balance or take possession.
  3. Check both on the project's MahaRERA page, where developers upload approvals. How to check a project on MahaRERA

Under RERA the developer must obtain the OC and hand over possession by the completion date stated in the registration. If the date keeps moving, the project's MahaRERA page shows each extension.

Questions buyers ask

What is the difference between OC and CC?

A Commencement Certificate (CC) is the permission to start construction according to the approved plans. An Occupancy Certificate (OC) is issued after construction and certifies that the building was built as approved and is fit to live in.

Can I move into a flat without an OC?

You should not. Occupying a flat without an OC can be treated as unauthorised, and it can delay permanent water and electricity connections, home loans, resale and society formation.

What is a part OC?

A part OC covers only some towers, wings or floors of a project that are complete. Check that it covers your tower and floor before you take possession.

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