This study examines the influence of supplier dynamics specifically knowledge of electronic tendering, attitudes toward electronic invoicing, and supplier communication on e-procurement performance within Tanzania’s cement manufacturing sector, focusing on Nyati and Twiga Cement in Dar es Salaam. Using descriptive cross-sectional research design and quantitative approach, data were collected from 86 purpsively selected respondents through structured questionnaires and analyzed using descriptive statistics, Pearson correlation, and multiple regression analysis. The results revealed that supplier knowledge and communication significantly and positively influence e-procurement performance, while attitude toward electronic invoicing had a positive but statistically insignificant effect. The model explained 63.7% of the variance in procurement performance, demonstrating that supplier-related factors are critical to the effective implementation of e-procurement systems. The study concludes that enhancing supplier knowledge, fostering effective communication, and strengthening digital capacity are essential for improving procurement efficiency and supplier–buyer relationships. It recommends targeted training programs, improved communication frameworks, and continuous system evaluation to optimize the National e-Procurement System (NeST) and advance digital transformation within Tanzania’s procurement sector.