The longer you allow delinquent property taxes to go unpaid, the more penalties and interest will stack up. If your property boundaries span more than one county you will receive appraisal notices from each county appraisal district. If unpaid, penalties and interest will accrue in both districts. 

Taxes are due when you receive your tax statement. Tax collections begin around October 1 and taxpayers have until January 31 of the following year to pay their taxes. On February 1 penalty and interest charges begin accumulating on most unpaid tax bills.