If you use ecommerce for local and in-state sales chances are you have to track and pay sales tax.  Here’s what to do if you use PayPal “Buy Now” or Add to Cart buttons on your website and your state or local sales taxes change.

Here’s how to set up your sales tax rates:

• Log in to your PayPal account.
• Click the Business Profile icon next to “Log Out” and select Profile and settings.
• Click My selling tools.
• In “Selling online”, click Update next to “Sales tax.”
• Click Add New Sales Tax.
• Choose the states for which you are setting up tax rates.
• Enter a tax rate. Only click “Apply rate to shipping amount” if your state requires it.
• Click Continue, or click “Create Another” to set up another sales tax.

Source: PayPal Help Center