Abstract
<jats:p>The interface design plays a vital role in meeting the requirements of usability, which is the essence of user experience. With the growing trend of digitalization in nearly every process within any system, the quality of human-system interaction has become much more important than ever. In this study, the evaluation of user interfaces for sales applications in the telecommunications sector is considered. By utilizing fundamental techniques, namely the System Usability Scale (SUS), the User Experience Questionnaire (UEQ), Nielsen's heuristics for usability, and the relevant parts of the ISO 9241 standard, a user interface evaluation questionnaire is proposed. The presented questionnaire structure consists of five sections, and it is applied in a company in the telecommunications sector.</jats:p>