In Oklahoma, up to 100 square feet of a storm shelter added after January 1, 2002 is exempt from property tax. You claim it once, on form OTC 905 with your county assessor, and file by March 15 to claim it for that tax year.

Cutaway illustration of a house with a steel storm shelter below the garage floor, its area outlined on the slab
A shelter below the garage floor, its small footprint outlined on the slab.

Where the rule comes from

The exemption is written into the Oklahoma Constitution, in Article X, Section 6. It covers a shelter built to protect people from tornadoes, including a safe room built inside the house. Oklahoma Emergency Management’s SoonerSafe FAQ points homeowners to the same rule.

What counts

  • Size: up to 100 square feet of the shelter. A bigger safe room is exempt only up to that limit.
  • Date: the shelter was installed or added after January 1, 2002.
  • Property: a home or a commercial building. It does not have to be your homestead.
  • Owner: you must own the property on January 1 of the year you claim it.

The OTC 905 form has boxes for a shelter inside the house, detached from it, or inside the garage.

How to claim it

Get form OTC 905 from your county assessor. Gather these details before you fill it out:

  • the type: in-ground, safe room or other
  • the size
  • what it is built of, such as concrete or steel
  • where it is: inside the house, detached, inside the garage or elsewhere
  • the date it was put in
  • what it cost

File it with the county assessor. You can file any time of year. But a form filed on or before March 15 counts for the current tax year, and one filed later counts from the next year.

Keeping the exemption on your property record

Once the assessor grants the exemption, you do not have to reapply each year. It ends when the property is sold or the title passes to someone else. In that year, the constitution says the shelter is assessed at its fair cash value.

Get the paperwork right from the start

Ask the installer for the details you need to complete OTC 905. When you request a free quote through the form, ask for a written price that states:

  • the shelter’s floor size in square feet
  • the material, steel or concrete
  • where it will go: house, garage or yard
  • the full installed cost

Keep the final paid invoice with the installation date on it. If you are also planning around a rebate, read the SoonerSafe guide before scheduling installation.