E-commerce is a distribution method rather than a product category, so the right class depends on what your e-commerce business sells or provides.
If you sell physical goods under your brand, the relevant classes are the goods-specific ones corresponding to your products. If you operate a marketplace selling multiple brands' products, Class 35 (retail services) covers that activity. If you provide technology or platform services underlying the e-commerce operation, Class 42 (IT and software services) is relevant. If you sell digital content or provide subscription services, Classes 41 or 42 may apply depending on the nature of the content.
For most e-commerce businesses, the starting point is identifying the primary commercial offering and selecting the class that covers it directly. Not sure which applies? Get a free class recommendation with Trama.