Merchants are classified as “low-risk” (normal risk) or “high-risk” based on several factors. For example, if you have an average monthly sales volume of over $20,000 and your average card transaction is over $500, you could be labeled high-risk. If you have a lot of chargebacks or sell to high-risk countries, that could also get you classified as high-risk.
Other factors that could get you labeled high-risk include whether you accept multiple currencies, sell seasonal products, or offer recurring subscription products.