The abbreviations on a property tax bill fall into a handful of groups: codes that identify your parcel, terms that describe how it was valued, labels for exemptions, designations for the taxing authorities taking a share, shorthand for how ownership is recorded, acronyms for appeal bodies, and codes for late-payment charges. Once you know which group a code belongs to, the bill starts reading like a document instead of a puzzle.
Codes That Identify Your Parcel
Every taxable property has a unique tracking number. The most common labels are PIN (Parcel Identification Number) and APN (Assessor’s Parcel Number). Some jurisdictions use PID (Parcel Identifier) or Property Index Number. The name changes; the job doesn’t. The number ties a physical piece of land to a single record in the county’s assessment database, and it’s what the assessor’s office needs when you call or search online.
Formats vary. Some counties use a compact 8- or 10-digit string. Others use 19 digits with hyphens separating segments for municipality, section, range, and lot. The number usually prints near the top of the bill and on your annual assessment notice.
Parcels described under the Public Land Survey System carry S-T-R, for Section-Township-Range. Township indicates a location north or south of a baseline; range indicates east or west of a principal meridian. Properties in platted subdivisions use Lot/Blk (Lot and Block) instead, which pinpoints the parcel within a recorded subdivision plat. Both are permanent legal identifiers and change only if the land is formally subdivided or consolidated.
You may also see a reference to GIS (Geographic Information System). Many county assessor sites offer a GIS map tool that lets you look up any parcel by address or PIN and view boundaries, acreage, and often the assessed value on the screen.
Valuation and Assessment Terms
The financial section of the bill is a chain, each link abbreviated, that starts with what your property is worth and ends with the number your tax rate multiplies against.
FMV (Fair Market Value), sometimes shown as MV or TCV (True Cash Value), is the assessor’s estimate of what the property would sell for in a normal, arms-length transaction. Assessors update it using comparable sales, construction cost data, and — for commercial properties — income analysis.
Not every jurisdiction taxes the full market value. Many apply an LOA (Level of Assessment), the percentage of market value that becomes the official assessment. If your LOA is 10 percent and your FMV is $300,000, your AV (Assessed Value) is $30,000. Some states assess at 100 percent, making FMV and AV identical. Others use fractions as low as 4 percent. Your bill may print the LOA as a decimal or a percentage, or just show the resulting AV.
After exemptions and legal caps come off the assessed value, you have TV (Taxable Value). This is the number your tax rate actually hits. Many states cap how fast TV can grow year to year, often limiting the annual increase to the lesser of inflation or a fixed figure like 5 percent. That cap can hold your taxable value well below your market value in a rising market, but it typically resets when the property changes hands, so a new buyer may face a much higher TV than the previous owner did.
You’ll also see ad valorem on many statements. It’s Latin for “according to value” and simply means the tax is based on what the property is worth rather than a flat fee. The distinction matters when your bill also carries non-ad valorem charges, such as special assessments for road paving or sewer work, which are flat charges based on the cost of a specific improvement.
Mill Rates and the Calculation
One mill equals one-tenth of a cent, or one dollar of tax for every $1,000 of taxable value. A rate of 25.5 mills means $25.50 per $1,000 of TV. Some jurisdictions express the rate in mills, some as a percentage, some as dollars per hundred. All three describe the same thing in different units.
The formula: taxable value divided by 1,000, multiplied by the millage rate, equals the tax. A home with a TV of $200,000 at a total millage of 20 mills owes $4,000. That total millage is almost always the sum of several individual levies from different taxing authorities, each on its own line.
ETR (Effective Tax Rate) is your actual bill divided by full market value, expressed as a percentage. Because assessment ratios, exemptions, and caps all shrink the base the tax is calculated on, the effective rate is usually lower than the headline millage rate suggests. Comparing effective rates across communities is a more honest measure of relative burden than comparing raw millage.
Exemption Codes and Property Class Codes
Exemption codes represent money you’re saving. If you qualified for one and its code isn’t on your statement, you’re being taxed at the full rate.
- HS or HX (Homestead) reduces the taxable value of your primary residence. The dollar amount varies widely. Some jurisdictions exempt a few thousand dollars of assessed value; others exempt $100,000 or more. You generally have to apply through the assessor’s office and prove the property is your primary residence.
- SR or SX (Senior) is age-based, usually requiring the owner to be 65 or older, and often subject to an income ceiling. Some jurisdictions require annual reapplication with proof of age and income.
- DIS or DX (Disability) reduces the bill for property owners who meet specific disability criteria, including programs limited to disabled veterans. Documentation typically involves medical certification or a VA disability rating.
- AG (Agricultural) values land based on its productive capacity rather than development potential, which usually produces a dramatically lower assessed value. Losing AG classification can trigger a sharp increase, sometimes retroactively.
Property class codes like R1, R2, R3, C1, or I1 describe use classification. R1 typically means single-family residential, R2 a duplex, R3 multi-family, C commercial, and I industrial. Classification matters because different property types may be assessed at different percentages of market value or taxed at different rates. A single-family home mistakenly coded outside the residential category can inflate the bill on its own.
Every exemption has a filing deadline, and missing it usually forfeits the benefit for that tax year. Most assessors won’t apply an exemption retroactively without going through a formal correction process.
Taxing Authority and District Codes
A property tax bill isn’t one tax. It’s a bundle of levies from every government entity authorized to tax the parcel, aggregated into one payment with the breakdown listed on the statement.
- ISD (Independent School District) is usually the largest single share, often 50 to 70 percent of the total bill, funding teacher salaries, operations, and building maintenance.
- MUD (Municipal Utility District) is a special-purpose district that finances water, sewer, and drainage infrastructure through bonds repaid by property taxes within its boundaries. MUDs are especially common in newly developed areas.
- CCD (Community College District) is a levy for community or junior college funding.
- VLG (Village), TWP (Township), CTY (County), and CITY identify the layer of local government collecting for police, fire, roads, parks, and general services.
- TIF (Tax Increment Financing), sometimes shown as TIRZ or a similar acronym, indicates the parcel sits inside a district where the additional tax generated by rising property values (the “increment”) is captured for development projects in the designated area rather than flowing to the general funds of the other taxing bodies.
Each authority sets its own rate, and rates don’t always move in the same direction. When your total bill jumps, check whether the change came from a higher assessed value, a higher millage from one of these entities, or both.
Ownership Abbreviations
The owner-of-record section often uses Latin shorthand and legal abbreviations that carry real meaning about how title is held.
- Et al means “and others” and indicates multiple owners beyond those named.
- Et ux means “and wife” (or spouse); et vir means “and husband.” Either shows the property is held jointly with a spouse.
- TC (Tenants in Common) means each owner holds a separate share that can be sold or inherited independently.
- JTWROS or JT (Joint Tenants with Right of Survivorship) means a deceased owner’s share passes automatically to the surviving owner.
- TR or TRST indicates the property is held in a trust, with the named person as trustee.
- LE (Life Estate) gives one person the right to use the property for their lifetime, after which it passes to a designated remainderman.
- TOD (Transfer on Death) designates a beneficiary who will receive the property outside probate.
- EST (Estate) means the owner is deceased and the property is being administered through their estate.
- LC or LCH (Land Contract or Land Contract Holder) means the property is being purchased under a land contract, and the bill may go to buyer or seller depending on the contract terms.
Getting the ownership designation wrong can create problems at title transfer or in estate planning. A bill showing tenants in common when you intended joint tenancy with survivorship produces very different results at death. Flag any discrepancy with the assessor’s office and your attorney.
Appeal and Correction Abbreviations
If you think your assessment is wrong, you’ll run into a separate set of acronyms tied to the review process. Names differ by jurisdiction, but the structure is broadly similar: an initial local review, with the option to escalate.
- BOR (Board of Review) is often the first body to hear assessment appeals. It reviews your evidence and the assessor’s evidence and issues a decision. Filing deadlines are strict and tied to local schedules.
- BOE (Board of Equalization) serves the same function in states that use that name instead of, or alongside, a Board of Review.
- PTAB (Property Tax Appeal Board) is a state-level body in some jurisdictions that hears appeals from owners dissatisfied with the local decision. Petitions typically must be filed within 30 days of the local ruling.
- COE (Certificate of Error) corrects a mistake on a bill that has already been issued, such as a missed exemption or a valuation error for prior years. It isn’t a forward-looking appeal; it fixes a specific past mistake.
Appeals usually cost little in filing fees, but they require evidence: recent comparable sales, photos of property condition, or an independent appraisal. Appeals commonly fail when the owner felt the value was too high but brought no data.
Penalty, Interest, and Payment Codes
Codes in the amount-due section usually relate to late charges or how the taxes are being collected.
- DEL (Delinquent) indicates the payment is past due and enforcement charges have begun.
- PEN (Penalty) is a surcharge on the unpaid balance. Rates vary, typically running from about 1.5 percent per month to a flat 10 or 20 percent of the unpaid amount.
- INT (Interest) accrues on the delinquent balance, usually calculated monthly, on top of any flat penalty.
- ESC (Escrow) means a mortgage lender is collecting a monthly amount bundled into your mortgage payment and paying the tax bill on your behalf. Some lenders call this “impound.” Confirm the escrow payment actually reaches the tax collector, because the lien attaches to the property regardless of whether a missed payment was the lender’s fault.
Unpaid property taxes eventually produce a tax lien that takes priority over almost all other debts on the property. If the delinquency continues, the property can be sold at public auction or tax sale to satisfy the debt. Once a lien is recorded, it appears on title searches and can block any refinance or sale.