AZ HB2594

Modifies the definition of "alteration" in Arizona's transaction privilege tax (TPT) law to exclude increases in square footage of existing residential structures under the roof.

Changes the threshold for residential property alterations from 25% to 15% of the most recent full cash value before a project is considered a modification subject to prime contracting tax.

Adds a new definition of "residential" property that includes class two, three, and four properties used for residential purposes under Arizona property tax classifications.

Applies to all contracts, bids, or binding obligations entered into on or after December 31, 2024.