> Sellers have the right to refuse your exemption certificate, even if it is correct and properly completed. A seller that refuses your certificate must charge you sales tax. You may apply for a refund of the sales tax using Form AU-11, Application for Credit or Refund of Sales or Use Tax. For more information, see Tax Bulletins How to Apply for a Refund of Sales and Use Tax (TB-ST-350) and Sales Tax Credits (TB-ST-810).
> Apple Store purchases will include sales tax based on the ship-to location and the sales tax rate in effect at the time of shipping unless proof of state tax-exemption is provided. To assure that your order is tax exempt, please call Apple Store Sales Support at 1-800-793-9378. Be prepared to provide proof of state tax-exempt status for the state where the product is shipping. The organization or individual name on the order must exactly match the state tax-exempt certificate.
> Sellers have the right to refuse your exemption certificate, even if it is correct and properly completed. A seller that refuses your certificate must charge you sales tax. You may apply for a refund of the sales tax using Form AU-11, Application for Credit or Refund of Sales or Use Tax. For more information, see Tax Bulletins How to Apply for a Refund of Sales and Use Tax (TB-ST-350) and Sales Tax Credits (TB-ST-810).
Here is Apple's policy:
https://store.apple.com/Catalog/US/Images/federalSalesPolici...
> Apple Store purchases will include sales tax based on the ship-to location and the sales tax rate in effect at the time of shipping unless proof of state tax-exemption is provided. To assure that your order is tax exempt, please call Apple Store Sales Support at 1-800-793-9378. Be prepared to provide proof of state tax-exempt status for the state where the product is shipping. The organization or individual name on the order must exactly match the state tax-exempt certificate.