Navigating and solving problems in everyday life is crucial to living independently throughout adulthood. Using real-life scenarios, the Everyday Problems Test (EPT; Willis & Marsiske, 1993) is a pen-and-paper test used to assess such everyday problem solving. This test was developed according to the seven scales of the Instrumental Activities of Daily Living (IADL; Lawton & Brody, 1969) and validated in a sample of only older adults. However, not all items of the original EPT are up-to-date and applicable outside the US. Therefore, we developed and validated a new online short form of the EPT that can be used in different countries and assessed its validity across the full adult lifespan. We constructed an English, French, and German EPT version with each 14 items to be implemented within a multi-site cognitive training study taking place in three countries: the UK, Canada, and Germany (von Bastian et al., 2022). Within this multi-site study, participants (N = 424; M age = 48.2; range age = 18-85) were asked to complete the 14-item EPT in their respective language along with various other cognitive tasks. Overall, the new short form of the EPT is sensitive to effects of age and education. Performance on this test of everyday problem solving relates strongly to participants’ abilities to solve other reasoning tasks. The relationship between problem solving in an everyday context and the performance in cognitive domains such as working memory, inhibition, and processing speed will be further analyzed and discussed.