If you own property in Philadelphia, three acronyms decide what you pay: the OPA, the BRT, and the assessed value they produce. They sound bureaucratic, but the ideas underneath are simple — and understanding them is the difference between accepting a tax bill and knowing whether it's fair. This is the plain-English version.
The OPA is the City of Philadelphia's Office of Property Assessment. It is the government office with one central job: to determine the assessed value — meant to reflect market value — of every property in the city, from a Fishtown rowhome to a Center City tower. That value is the foundation of your annual property tax bill, so the OPA's estimate directly sets what you owe.
To value hundreds of thousands of parcels at once, the OPA uses mass appraisal: instead of a person walking through each home, a statistical model estimates values in bulk from characteristics like size, location, and — crucially — the prices of nearby homes that have recently sold. It's the only practical way to assess an entire city on a schedule, and for typical homes on active blocks it works reasonably well. Its weaknesses show up on properties that don't fit the pattern.
People mix these up constantly, so here's the clean line: the OPA assesses, the BRT reviews. The Board of Revision of Taxes (BRT) is a separate body that hears formal appeals of the values the OPA sets. If you think your number is wrong, the BRT is where you formally contest it.
There's also a gentler first step. Before going to the BRT, you can ask the OPA to reconsider its own value through a First Level Review — an informal request, using the form and deadline printed on your annual assessment notice, that sends the question back to the office that made the assessment in the first place. Many owners start there. The two paths are not mutually exclusive dead ends: the First Level Review is the quick, informal ask to the OPA, and the BRT appeal is the formal challenge to an independent board. Neither requires a lawyer.
OPA sets the number. The First Level Review asks the OPA to look again. The BRT is the formal appeal to an independent board.
In Philadelphia the OPA's assessed value is intended to equal your property's market value — what it would sell for in an ordinary sale. That single number drives your bill through a straightforward formula: assessed value multiplied by the tax rate. The combined effective rate is roughly 1.4% (1.3998%) of assessed value, so a home assessed at $300,000 carries a bill in the neighborhood of $4,200 before any exemptions.
The consequence is worth sitting with: because the bill is a fixed percentage of the assessed value, an assessment that's set too high doesn't cost you once — it costs you every year until it's corrected. We walk through the exact arithmetic in how your Philadelphia property tax is calculated.
Mass appraisal is a model, and models generalize. On a block of near-identical rowhomes that trade often, the OPA has plenty of clean data and usually lands close. But the moment a property is unusual — larger than its neighbors, in unusually good or poor condition, on an odd lot, or in an area where few homes sell — the model has to reach. Reaching is exactly how it lands a value above what the property would actually fetch.
That's not a scandal; it's the known limitation of assessing a whole city at once, and it's precisely what an appeal exists to correct. An appeal doesn't accuse anyone of bad faith — it simply shows, with genuinely comparable recent sales, that the model's estimate for your specific home is off. To find out whether yours is, start with the self-check in is my home over-assessed?, and if it is, how to appeal your Philadelphia assessment lays out the steps.
Everything above is abstract until you look at your own numbers. The OPA maintains a public property search on the City of Philadelphia's website, phila.gov, where you can enter any address and pull up its current assessed value, the characteristics on file — square footage, story count, condition flags — and its assessment history. It's free and open to anyone.
Reading that record is the essential first move, because two things can be wrong: the value itself, or the underlying facts the value was built on. An overstated square footage or a wrong room count is one of the cleanest grounds for a reduction. Our guide to checking your assessment shows you where to find the search and what to look for once you're in it.
OPA is the City of Philadelphia's Office of Property Assessment. It is the government office responsible for determining the assessed (market) value of every property in the city — the value that your annual property tax bill is calculated from.
The OPA assesses; the BRT reviews. The Office of Property Assessment sets each property's value. The Board of Revision of Taxes is a separate body that hears formal appeals of those values. Before a formal BRT appeal, you can also ask the OPA to reconsider informally through a First Level Review. In short: OPA sets the number, and the BRT is where you formally challenge it.
Assessed value is the OPA's estimate of what your property would sell for — in Philadelphia it is meant to reflect market value. Your tax bill is that value multiplied by the tax rate, which is roughly 1.4% (1.3998%). So a higher assessed value means a higher bill, and an assessed value set too high means you overpay every year until it is corrected.
Yes. If you believe your assessed value is too high, you can ask the OPA to reconsider through an informal First Level Review, or file a formal appeal with the Board of Revision of Taxes. No lawyer is required, and the strongest cases are built on genuinely comparable recent sales that show your value is out of line.
The OPA maintains a public property search on the City of Philadelphia's website, phila.gov, where you can look up any address and see its current assessed value, property characteristics, and history. Reviewing that record is the first step in checking whether your assessment is accurate.
TaxAssessmentIQ gives you a free, honest verdict from the City's own recorded sales — just enter your address, no sign-up and no account. If your home looks over-assessed, you can get a ready-to-file appeal packet for a flat, one-time price, backed by a money-back guarantee. If it isn't worth filing, we tell you that too — for free, before you pay anything.