Amazon collects sales tax in only five states — Kansas, Kentucky, New York, North Dakota and Washington — where it has offices or another physical presence. It avoids collecting in several other states where it has warehouses by assigning their ownership to a subsidiary. Until the tax dispute in Texas, Amazon had encountered few problems with that arrangement. Now, though, as Amazon seeks to open warehouses in South Carolina and Tennessee, it is also pressing for specific legislation to exempt it from collecting sales tax, using the jobs created by the facilities as leverage.