Why the first bill surprises new owners
The most common surprise for new San Antonio-area buyers isn't the tax rate — it's timing and the transfer effect. Property tax bills are typically mailed by the county tax assessor-collector in October and due by January 31 of the following year without penalty; interest and penalties begin accruing February 1 on unpaid balances. Bexar County uses the Bexar Appraisal District (BCAD) for valuation; if you bought in Comal, Guadalupe, Kendall, or Wilson County instead, a different central appraisal district set your value. Many counties reassess a property toward its actual sale price in the year following a transfer, since the sale itself becomes the strongest evidence of market value the appraisal district has seen. That means the prior owner's tax bill — the number a listing agent may have quoted during your search — is often not a reliable predictor of what you'll owe.
How appraisal districts value your home
Each central appraisal district (BCAD for Bexar County, and separate districts for Comal, Guadalupe, Kendall, and Wilson counties) estimates market value as of January 1 each year, using recent comparable sales, permits, and mass-appraisal models. Appraisal notices generally go out in the spring. Your actual bill isn't just that appraised value times one rate — it's the sum of separate rates set by every taxing unit with authority over the property: the county, the city (if inside city limits), the school district, sometimes a community college district or hospital district, and any special districts like a MUD or emergency services district. Each taxing unit sets its own rate through its own budget process, typically finalized in August or September, which is part of why the bill doesn't show up until fall even though the appraised value was set months earlier.
The homestead exemption: what it does and how to file
If the home is your principal residence as of January 1, you can file for a general residence homestead exemption with the county appraisal district — it's free to file, and no company that charges a fee to "file it for you" is doing anything you can't do yourself on the appraisal district's website. The exemption reduces the taxable value the school district (and, depending on local adoption, other taxing units) can tax you on; the Texas Legislature raised the general homestead exemption substantially in recent years, so confirm the current dollar amount with your appraisal district rather than relying on an old figure. The homestead exemption does not transfer from the seller — you have to file your own application after closing, generally by April 30 of the tax year, though late filing is allowed for a period after that. Filing late doesn't cost you the exemption for future years, but the sooner it's on file, the sooner it applies.
The 10% cap, and why year one looks different
Once a homestead exemption is in place, Texas law caps how much the taxable value of that home can increase each year for as long as you own and occupy it — generally 10% per year over the prior year's appraised value, excluding the value of new improvements. That cap is a real, durable benefit for long-term owners, and it's a big reason a longtime owner's tax bill can look dramatically lower than a next-door neighbor's after a recent sale. The catch: the cap doesn't protect you in the year you buy. If the appraisal district reassesses the property to your purchase price the year after closing, that first jump can be a meaningful increase over what the seller was paying — after which the 10% cap starts applying going forward, once your own homestead exemption is on file.
Over-65, disabled, and disabled veteran exemptions
Beyond the general homestead exemption, several other exemptions can reduce the bill further. Homeowners who are 65 or older, or who qualify as disabled, can generally claim an additional exemption amount and — critically — a school-tax ceiling that freezes the school portion of the bill at a set dollar amount going forward (with some exceptions for new improvements), and that ceiling can generally be transferred to a new homestead if you move within Texas. Disabled veterans qualify for a separate property tax exemption tied to their VA disability rating, scaling up to a full exemption on the homestead at a 100% rating or individual unemployability determination. None of these apply automatically — each requires its own application and supporting documentation filed with the appraisal district, and exact amounts and rules are set by state law and can change, so verify current specifics before assuming a figure.
MUD, PID, and add-on assessments
In many newer San Antonio-area communities — including large sections of Veramendi in New Braunfels and other master-planned developments still building out infrastructure — a Municipal Utility District (MUD) or Public Improvement District (PID) layers an additional assessment on top of standard county, city, and school taxes to pay down the bonds that funded roads, water, and sewer infrastructure for that community. A MUD rate is a real, recurring cost that belongs in your total housing-cost math alongside the base ad valorem tax rate, and it generally declines over time as the district retires its bond debt — but the pace of that decline varies district to district. Before writing an offer in a MUD or PID community, ask for the current combined tax rate (not just the county/city/school portion) and the district's most recent bond disclosure or annual report, which your title company or the builder's sales office can typically provide.
Protesting your value and budgeting for the bill
You can protest your appraised value every year, not just the year you buy — and it's worth reviewing the notice annually, especially in a year where the appraisal district's estimate looks out of step with actual comparable sales. The protest deadline is generally May 15 or 30 days after the notice was mailed, whichever is later; most appraisal districts now offer an online informal-review process before an in-person Appraisal Review Board hearing is needed. If your mortgage has an escrow account, your lender estimates the annual tax and insurance cost and collects it in your monthly payment — but escrow estimates can undershoot in year one before the true post-sale reassessment lands, which can mean an escrow shortage and a higher payment the following year. If you don't escrow, block out the October-to-January window on your own calendar and budget for the full bill rather than assuming it will match what you saw quoted during the home search.