The transition of a business to the online space stopped being a fashionable trend long ago — today it is a necessity for survival and growth. However, even companies with offline sales experience often repeat the same mistakes that complicate the launch or slow down development. The online environment has its own rules, where technical stability, user convenience, and understanding of digital tools become crucial. To avoid unnecessary expenses and losing customers, it is worth understanding which mistakes businesses most often make during digitalisation and why they become critical.