Texas imposes a 6.25 percent state sales and use tax on all retail sales, leases and rentals of most goods, as well as taxable services. If you are not registered for GST, make purchase order which will show all prices as GSTinclusive and make no mention of GST.This is the total of state, county, and city sales tax rates. A sales tax exemption certificate is needed in order to make taxfree purchases of items and services that are taxable. If you sell your own goods only online , then requirement of GST registration depends on your turnover in a year. You must obtain a Texas sales and use tax permit if you are an individual, partnership, corporation or other legal entity engaged in business in Texas. When you make a sale, request the buyer's GST number. Businesses will have one, private individuals will not. The completed exemption application must be filed with the Tarrant Appraisal District before May 1st. If you sell your own goods only online , then requirement of GST registration depends on your turnover in a year.