If you're running an online business, odds are that you'll have some sort of system through which you can receive payments. Even if you just send your bills through PayPal or a similar system, it can sometimes be helpful to indicate what payment methods are accepted. Along with this, you can also use the icons to guide the user through an intuitive payment system if you use the right icons.
In this post, we've gathered up 15 awesome, high quality, free icon sets from around the web that you can use in your commercial projects. Whether you're running a small design firm, or a giant online sales business, these icons will suit your needs.