Retail strips, office floors, multi-unit apartments, and mixed-use buildings with a shop below and flats above are valued by a very different logic than a single-family home — and that logic is exactly where over-assessment hides. When value is supposed to flow from income, the assumptions behind that income are where a Philadelphia commercial assessment most often goes wrong.
The Office of Property Assessment (OPA) sets assessed (market) values across hundreds of thousands of parcels using mass appraisal. For income-producing property it leans on an income approach: estimate the market rent a building should command, subtract an assumed vacancy allowance and assumed operating expenses to reach net operating income, then capitalize that into a value. In principle that mirrors how a buyer would price the building. In practice, doing it at scale means the rent, vacancy, and expense figures are generalized — drawn from a class of buildings, not from your rent roll.
That is the opening. A model's assumed income is a stand-in for your building's real income, and the two rarely line up.
Because value tracks income, any gap between the model's assumed economics and your building's actual economics moves the number — usually in your favor. The recurring misses:
Commercial property is where the distance between a generalized model and a real rent roll is widest — and that distance is what a documented appeal turns into a reduction.
Start by asking whether the assessment implies rent, vacancy, and expense figures your building actually experiences, and whether it lines up with what comparable income properties have traded for. Our comparable-sales guide covers how to adjust for differences defensibly, and the self-check walkthrough shows the underlying math you can apply to an income property as well.
Then check the record for plain errors, because those are the cleanest grounds of all. A wrong square footage, an outdated use code, or an incorrect unit count on the OPA record is a factual mistake that supports a reduction on its own — verify it before anything else, and build the rest of the case on top of it. Our guide to gathering the evidence that wins walks through what to pull together, from the rent roll to the expense statements.
Commercial and mixed-use owners use the identical two-track process as residential owners. You can begin with a First Level Review, an informal request that OPA reconsider using the form and deadline printed on your annual notice. Or you can file a formal appeal to the Board of Revision of Taxes, whose deadline is generally the first Monday in October of the year before the tax year — always confirm the current-year date at phila.gov or the BRT site, since it shifts with the calendar. Our BRT appeal guide lays out the formal path step by step.
No lawyer is required for either track. Larger owners and institutional portfolios sometimes retain counsel or an appraiser for a high-value hearing, but the filing right belongs to the owner, and the case is won on documents, not representation. At roughly 1.4% of assessed value (1.3998%), even a modest percentage correction on a commercial building is a meaningful annual saving that recurs until the next reassessment.
The hard part of a commercial appeal is assembling the proof: pulling your live OPA record, checking it for factual errors, and lining up the income and comparable evidence that shows the model's assumed economics aren't your building's real ones. TaxAssessmentIQ does that groundwork, tells you whether the gap is worth appealing, and generates a Board of Revision of Taxes–ready packet — so all that's left is to sign, attach your rent roll and expenses, and send.
The Office of Property Assessment values income-producing property largely through mass appraisal, leaning on an income approach: it estimates market rent, vacancy, and operating expenses to arrive at a value. Because it does this across many parcels at once with generalized assumptions, the rent, vacancy, and expense figures behind your number are often not the ones your building actually experiences.
Because value flows from income, and the model's assumed income rarely matches the real building. If your actual vacancy runs higher than the model assumed, or your operating expenses, concessions, or below-market leases cut your net operating income, the true value is lower than the assessment. Commercial property is where the gap between a generalized model and your real rent roll is widest, which is exactly what a documented appeal exploits.
Commercial and mixed-use owners use the same two tracks as everyone else: an informal First Level Review with OPA, using the deadline printed on your annual notice, and a formal appeal to the Board of Revision of Taxes. The formal BRT deadline is generally the first Monday in October of the year before the tax year — always confirm the current-year date at phila.gov or the BRT site.
No. An owner can file a First Level Review or a formal Board of Revision of Taxes appeal without a lawyer. Larger owners and institutional portfolios sometimes retain counsel or an appraiser for high-value hearings, but the filing right is the owner's, and what actually moves the number is the evidence — the rent roll, the expenses, and comparable values.
The documents that show your building's real economics: a current rent roll, actual vacancy, operating expenses, lease terms, and any factual corrections to the OPA record such as square footage, use code, or unit count. A plain error in the record is clean grounds for a reduction on its own; beyond that, income and comparable evidence carry the case. The work is the evidence, and that is what TaxAssessmentIQ assembles.
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 property 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.