What is a certificate of occupancy, and does a house need one?

Updated October 6, 2026 · 4 min read

Short answer

A certificate of occupancy (CO) is the document a building department issues stating that a building may legally be occupied and for what use, such as a one-family home. It is normally issued when new construction or a major alteration passes final inspection. Many older houses never had one, and that alone is not a defect.

When one is issued

  • New construction, once it passes final inspection.
  • A change of use: one unit to two, a garage to living space, a house to an office.
  • Major alterations, in some cities.
  • Smaller jobs usually end with a signed-off final inspection instead. Some cities call the paperwork a certificate of completion.

Older houses often have none

Cities began requiring certificates at different times, and houses built before then were not made to get one. New York City is a clear example: its Department of Buildings states that buildings built before 1938 are not required to have a certificate of occupancy unless later alterations changed the use, egress or occupancy. An owner who needs proof of legal use can ask the department for a Letter of No Objection.

Temporary certificates

A temporary certificate of occupancy (TCO) allows a building to be occupied while minor items are finished. It has an end date. A house still running on a temporary certificate, or one that lapsed, has work the city has not signed off.

Why buyers check it

The certificate states the legal use. If the listing says three-family and the certificate says two-family, the third unit is not legal, which affects the rent you can count on, the loan and the insurance.

How to find one

  1. 1Search the city's building records by address. Many cities publish certificates alongside permits.
  2. 2If nothing is online, ask the building department for the certificate on file.
  3. 3Ask the seller for a copy.
  4. 4Compare the use and number of units on the certificate with the listing and with what you see in the house.

Common questions

Is a certificate of occupancy the same as a permit?

No. A permit authorizes work. A certificate of occupancy says the finished building may be occupied for a stated use.

Can you sell a house without a certificate of occupancy?

Often yes, where the house was never required to have one. Some municipalities require a new certificate or inspection at each sale. Ask the local building department.

What if the certificate does not match the house?

Then some of the house's current use was never approved. Ask the seller what was changed and whether a permit covered it, and check the permit history.

Read next

Sources

This guide is general information, not legal advice. Permit rules vary by city and state. Confirm anything that affects a purchase with the local building department or a real estate attorney.