This study explores the relationship between time-based prospective memory (TBPM) performance and individual differences in working memory capacity, specifically focusing on binding and updating capacities. A total of 132 participants performed three working memory tasks (binding, updating, and operation span) and eight 5-min blocks of a TBPM task. The latter comprised a word-picture matching task as ongoing task with TBPM instructions to press a special key every five minutes. Participants could check a screen clock to monitor the time at any time during the ongoing task. We examined clock-checking strategicness by evaluating the frequency of checks in the final quarter of each block relative to the total number of clock checks throughout the block. Generalized Linear Mixed Models results indicated that higher working memory composite scores and more strategic clock-checking predicted superior PM performance, with updating abilities playing a pivotal role. We also found higher ongoing task accuracies but no accelerated response times in participants with higher working memory composite scores. These results suggest that both general cognitive-capacity (mainly in terms of updating) and task-specific strategic processes are crucial for maintaining an intended action until the planned execution time. This study contributes new insights into the interplay between working memory components and TBPM.