Three experiments investigated the impact of working memory load on on-line plan adjustment during a test of multitasking in young, non-expert, adult participants. Multitasking was assessed using the Edinburgh Virtual Errands Test (EVET -Logie, . Participants were asked to memorise either good or poor plans for performing multiple errands, and were assessed both on task completion and the extent to which they modified their plans during EVET performance. EVET was performed twice, with and without a secondary task loading a component of working memory. In Experiment 1 articulatory suppression was used to load the phonological loop.In Experiment 2, oral random generation was used to load executive functions. In Experiment 3, spatial working memory was loaded with an auditory spatial localisation task. EVET performance for both good and poor planning groups was disrupted by random generation and sound localisation, but not by articulatory suppression. Additionally, people given a poor plan were able to overcome this initial disadvantage by modifying their plans on-line. It was concluded that, in addition to executive functions, multiple errands performance draws heavily on spatial, but not verbal, working memory resources but can be successfully completed on the basis of modifying plans on-line, despite a secondary task load.3 Acknowledgements