Property appraisals are soon in the mail so… In many states property taxes are paid in arrears—you pay 2011 taxes in 2012. Not so in Texas. Here’s the timeline.
January 1 – Your property is appraised as of January 1st. In order for a home to claim the homestead exemption, the owner must reside in the property on January 1st. He can move out 
on the 2nd but the house must be owner-occupied on 1 January to claim the exemption. The exemption is good for all year. If the property becomes a rental later in the year, it makes no difference as far as the homestead exemption is concerned for that year.
January 1 – March 31 (or so) The Central Appraisal District (CAD) for the county in which the property is located will make their determination of the market value of the property for property tax purposes. Many times this is a “windshield” appraisal. The appraiser drives by, looks through his or her windshield, and says “ya, that’s about what it’s worth.”
Other times, the CAD uses “mass appraisal techniques” to determine the value of your property. Interestingly enough, one of the first principles taught aspiring real estate licenses is that all properties are unique, oh well.
The law requires periodic reappraisal of property and appraisal of real property at least once every three years. Many districts reappraise more often. Values for qualified residence homesteads may not increase more than 10 percent from the last reappraisal.
April 1 – July (or so :)) The appraisal review board (ARB) will (after hearings and due consideration) will approve and thereby create the official appraisal roll. An appraisal roll lists the taxable property within the boundaries of the taxing unit. The appraisal district’s job is finished for the current year. It has provided a set of equal and uniform values for all local taxing units to use.
July 1 – October 1 The assessor for each taxing entity receives the appraisal roll and using their tax rate against the values determines if amount of money will be adequate to fund their budget. If not, the entity raises the rate.
October 1- December 31 This is the collection period. Your taxes are due on October 1 and late after January 31st of the next year.
This is the “Reader’s Digest” condensed version of a long involved process. See the whole process here if you’re interested. 🙂