In June of 2018, there was a Supreme Court decision made called South Dakota v. Wayfair, Inc, which instated that online retailers are now required to collect sales tax in certain States where economic thresholds are met. The decision to collect and remit sales tax was by no means our own, however, we must abide by the law.
If you'd like to learn more, you can click this link below for more detailed information on the Supreme Court ruling. - https://www.avalara.com/us/en/learn/sales-tax/south-dakota-wayfair.html