We are committed to providing a simple and low-cost service for our authors. Tes absorbs the cost of both buyer credit card fees and seller withdrawal fees. These fees add up quickly for authors who publish only a few resources, and for authors who withdraw smaller royalty balances. Rather than pass along these fees or ask our authors to subscribe for higher royalties, we reward you based on how many resources you publish.
You only need to add 10 premium resources to reach Bronze author level, which means you'll have access to some really helpful sales tools (https://www.tes.com/teaching-resources/author-royalty), and only be charged a transaction fee on resources priced under £3/$3.
Further information can be found here: http://help-resources.tes.co.uk/customer/portal/articles/2832860-how-does-it-work-