Oklahoma property valuation notice: what changes November 1

Senate Bill 1579 took effect on November 1, 2026. According to the Oklahoma Tax Commission's 2026 tax legislation summary, it amends the ad valorem statute at 68 O.S. § 2876 so that a county assessor's notice of a valuation increase must include a taxpayer bill of rights, with wording the statute prescribes.

That sounds like a small change, and in one sense it is. The Oklahoma property valuation notice has always been the document that starts the protest clock. What changes now is that the notice must tell you, on its face, that the clock exists.

This piece dissects that notice step by step: what triggers it, what it must contain, how the mailing date is proved, and each deadline that runs from it. We separate what SB 1579 adds from what was already law, because the deadlines are not new and they do not forgive.

What triggers an Oklahoma property valuation notice

The assessor does not mail a notice for every parcel every year. Under the committee substitute text of SB 1579, which carries forward the existing structure of Section 2876, written notice is required in three situations.

• The assessor raises the valuation of your personal property above what you reported on your return.
• The assessor raises the fair cash value or the taxable fair cash value of your real property above the prior year.
• The assessor adds property you did not list, as the law requires the office to do.

Fair cash value is the assessor's estimate of what the property would bring in an arm's-length sale. Taxable fair cash value is the figure that actually feeds the tax calculation, which for many parcels is held below fair cash value by the constitutional growth cap. The second trigger covers either number moving, so a notice can arrive even in a year when the market estimate did not change.

For business owners, the first trigger is the one to watch. If you file a business personal property rendition and the assessor disagrees with your figures, the notice is how you find out. We covered the rendition side of that in our piece on Form 901; the notice of increase is the sequel.

Anatomy of the real property notice

The committee substitute lists what a real property notice must show. Each line has a purpose, and reading the notice line by line tells you whether a protest is worth the effort.

The value lines

First come the numbers. The notice states the fair cash value for the current year. It also states the taxable fair cash value for both the preceding year and the current year, and the assessed value for both years. Assessed value is taxable fair cash value multiplied by the county's assessment percentage, and that percentage must appear for both years as well.

Putting last year next to this year is the whole point. A jump in fair cash value with no change in taxable fair cash value usually means the cap is doing its work, and a protest would move nothing on the bill. A jump in taxable value, by contrast, is a jump in tax.

The homestead line

If the property is a homestead, the notice must include information about applying for the homestead valuation limit under Article X, Section 8C of the Oklahoma Constitution. That is a reminder, not an application; the limit still has to be claimed.

The taxpayer bill of rights

This is the SB 1579 addition. The OTC's legislation summary confirms the enacted bill requires the bill of rights and prescribes its language. The committee substitute we reviewed opens the list with the words "As an Oklahoma Taxpayer:" and then enumerates rights that include equal and uniform taxation, appraisal that is uniform with similar property, notice of value increases with the figures described above, the right to file a protest and request an informal hearing, the right to appeal the assessor's decision to the county board of equalization, and from there to district court and the Oklahoma Supreme Court.

One caution. The enrolled act is the version that governs, and we have read the committee substitute rather than the final enrolled text. The list above may differ in wording or order from what your county prints. Treat it as a guide to the kind of rights the notice will recite, not as the statute itself.

Why does a printed list of rights matter? In our experience the protest window closes on people who never knew it was open, and a notice that says "you have the right to file a protest" in plain words is the kind of thing that gets a notice handed to a CPA instead of filed in a drawer.

The personal property notice

A personal property notice is shorter. The committee substitute requires a description sufficient to identify the property, the current-year fair cash value and assessment percentage, the current-year assessed value, and any current-year penalty under the rendition statute. The personal property version is where a late or incomplete rendition shows up as a penalty line, which is another reason to compare the notice against what you filed.

The mailing date is the hinge

Every deadline that follows runs from one fact: the date the notice was mailed. The statute requires the notice to be sent to the taxpayer's last-known address and to be clearly marked with the date of mailing.

The assessor must also be able to reproduce the notice as mailed, showing that date, and that reproduction is prima facie evidence that notice was given. Prima facie evidence means the assessor's copy is presumed correct unless you can show otherwise. A notice that went to an old address after a move, or to a prior owner, is still a mailed notice for purposes of the clock.

Here is the practitioner's edge. When a valuation dispute reaches us late, the first question is never "is the value wrong?" It is "what date is printed on the notice?" Property owners tend to date the problem from the day they opened the envelope, or the day the tax statement arrived months later. The statute dates it from the mailing stamp, and the assessor's reproducible copy will say what it says.

Keep the envelope and the notice together. Note the day it actually arrived. If the mailing date and the postmark disagree, that is a fact worth preserving, even though the assessor's copy carries the presumption.

Clock one: 30 calendar days to protest

From the mailing date, a taxpayer has 30 calendar days to file a written protest with the county assessor. Calendar days, not business days, and the weekend counts.

The protest goes on the form the Tax Commission prescribes, which is OTC Form 974, County Assessor Informal Protest. The current revision (11-2025, for tax year 2026) states on its face that the taxpayer has 30 calendar days from the date the valuation notice was mailed, and that if the deadline is missed, the assessor's proposed values become final for that tax year.

Final means final. There is no late protest on the merits for that year, and the time to argue that the value was wrong is gone. The assessor does retain authority to correct a scrivener's error or an admitted error at any time, which can help when the problem is a transposed digit, but that is a correction, not a reconsideration.

What Form 974 actually asks

The form is a single page with a schedule of statutory provisions on the back. It asks for the property type, the account number, the owner's contact information, and the legal description. Then it asks the question that matters: if you believe the market value differs from the assessor's records, what is the proper value, and what evidence supports it?

Evidence boxes on the form are judgment sale, comparable sales, appraisal, and other. The form also asks whether the property was purchased within the last two years, and if so the date, the price, the seller, and the recording reference. An arm's-length purchase inside two years is often the single strongest piece of evidence a taxpayer has, and the form is built to surface it.

Form 974 instructs that the complaint set out the pertinent facts in ordinary and concise language. Resist the urge to write an essay. State the value you contend for, say what supports it, and attach the support. The committee substitute also provides that the form required under Section 2835 must accompany the protest, and that without it the assessor's valuation is presumed correct on appeal.

Clock two: the first Monday in April if nothing changed

A notice only issues when something went up. If the assessor left your values alone and you still think they are too high, there is no 30-day window because there is no mailing date. Instead, both Form 974 and the statute allow a protest on or before the first Monday in April.

Owners sometimes assume that a flat year is a year without recourse. It is not, but the April deadline is earlier than many expect, and it arrives before most people are thinking about property tax at all.

Clock three: the informal hearing and the seven-day decision

Once a protest is filed, the assessor schedules an informal hearing. The taxpayer may ask to attend in person or by phone, and Form 974 includes a box for that choice. If the taxpayer cannot make the scheduled date, the assessor must offer at least two additional opportunities, each with two alternative dates on different days of the week.

The hearing is informal in the sense that there is no judge and no rules of evidence. It is not informal in its consequences. The assessor's office will have its own data on the parcel, and the taxpayer should bring the comparables, the appraisal, or the closing statement that the protest form promised.

Within seven calendar days after the hearing, the assessor must issue a written decision. The decision is sent by regular or electronic mail and, like the notice itself, must be clearly marked with the date it was mailed. That date starts the next clock.

Clock four: 15 calendar days to the board of equalization

A taxpayer who disagrees with the assessor's written decision has 15 calendar days from the decision's mailing date to appeal to the county board of equalization. The appeal goes on the Tax Commission's form, which Form 974 identifies as Form 976, Formal Appeal County Board of Equalization, with one copy to the assessor and one to the board.

The committee substitute also carries a step that helps the taxpayer. After an appeal is filed, the assessor must provide the board with the materials the taxpayer submitted, the supporting data, and a written explanation of the informal hearing result. The record you built at the informal stage travels with you.

Form 974 also states the outer boundary: all protest proceedings must be completed by May 31 or the board's adjournment date, and it tells taxpayers to check with the county assessor for the exact date. The 15-day appeal clock sits inside that boundary, so a decision mailed in late spring leaves less room than the number suggests.

What SB 1579 changes, and what it does not

It is easy to read a new law as a new process. SB 1579 is not that. The enacted change the OTC summary describes is the required taxpayer bill of rights in the notice of increase. The 30-day protest window, the April fallback, the seven-day decision, the 15-day appeal, and the May 31 completion date are all pre-existing mechanics, and Form 974 as revised in November 2025 already recites them for tax year 2026.

So the practical effect is informational. The notice now carries its own instructions. The deadlines still run from the mailing date, and a bill of rights printed on the notice does not extend any of them.

A separate measure on the November 3 ballot, State Question 847, would change the valuation growth cap itself rather than the notice, and we covered it in our article on the proposed 4% cap.

When the notice is bigger than it looks

Most property tax protests are valuation arguments, and a competent appraiser or CPA can carry many of them. Some notices signal more than a number.

A notice that adds property you never listed can be the first visible sign that the assessor's office has a different picture of your business than your books do. A personal property notice with a penalty line raises the question of whether the rendition was filed at all, and by whom. A real property notice on a parcel held in an entity raises the question of who the last-known address belongs to, and whether anyone is watching that mailbox.

Think of the notice as a smoke detector rather than a bill. Most of the time it chirps because of a value change and you deal with the value. Occasionally it is telling you that the ownership records, the entity structure, or the filing responsibilities drifted while nobody was looking, and that is a legal problem wearing a tax problem's clothes.

The government-side view deserves a fair hearing too. The assessor's office is working from recorded sales and mass appraisal models, and a value that looks high in isolation may be well supported by the neighborhood data. The informal hearing exists so both sides can put their evidence on the table, and the 30-day window is generous enough to gather it if you start when the envelope arrives.

If a notice of increase has landed on a parcel or a business that matters to you, and the clock is already running, we would rather see it in the first week than the fourth. Reach us through the contact page or our Oklahoma City office. Sorting out a valuation protest early is generally far less expensive than discovering in July that the values became final in March.

This article is general information about Oklahoma, Texas, and federal law, not legal advice, and it does not create an attorney-client relationship. Facts matter; talk to a lawyer about yours.