701—219.19(423) Resale certificates. Whenever machinery and equipment which will remain tangible personal property after installation is purchased for a machinery and equipment contract by a contractor from a supplier or a material supplier, it should be purchased for resale. See rule 701—219.9(423). Resale purchases are most commonly related to machinery and equipment sales contracts with installation and mixed construction contracts. Contractor-retailers and persons making repairs may also purchase materials for resale as long as they collect tax on their retail sales and pay the tax themselves on items withdrawn from inventory for use in the performance of a construction contract. See rule 701—219.4(423) and subrule 219.13(1). Resale certificates can be obtained by contacting the Iowa department of revenue. Reference rule 701—288.3(423) for detailed information on resale certificates.