In enzymology, a phosphate acetyltransferase (EC 2.3.1.8) is an enzyme that catalyzes the chemical reaction

acetyl-CoA + phosphate ${\displaystyle \rightleftharpoons }$ CoA + acetyl phosphate

The substrates of this enzyme are acetyl-CoA and phosphate, whereas its two products are CoA and acetyl phosphate.

This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is acetyl-CoA:phosphate acetyltransferase. Other names in common use include phosphotransacetylase, phosphoacylase, and PTA. This enzyme participates in 3 metabolic pathways: taurine and hypotaurine metabolism, pyruvate metabolism, and propanoate metabolism.

As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes 1QZT, 1R5J, 1TD9, 1VMI, 1XCO, 2AF3, and 2AF4.