Buying THCA flowers online in the United States is generally legal as long as the product contains less than 0.3% delta-9 THC by dried weight. This threshold ensures that the product is classified as hemp and not marijuana, making it legal at the federal level, which by definition would include North Carolina. Most states also follow this guideline set by the federal government, allowing for the sale and purchase of THCA products online. However, individuals must be of legal age (21 years or older) to buy these products, and it is always important to check with your local laws before making a purchase.