The main thing is to separate payment gateways, which are suitable for startups, and payment gateways, which are great for small businesses. There is a difference in percentages and in some moments of using a payment gateway.

Such payment gateways usually lure clients with low interest rates. But there is one big disadvantage there, most likely there will be restrictions. For example, in Adien if you do not perform a minimum of 1000 transactions, then you have to pay the payment gateway $120 on top. If you consider paypal, then there are hidden fees, as well as 3% for transactions. Here by the way, you can read an article about how to create online payment website https://owlab.group/our-blog/post/best-payment-gateways-for-startups-and-small-businesses. All the payment gateways that you can use and connect to your business are also described there.