Please be aware that this site is informational only, and many external factors, unique to your company might apply. Each company must make their own decisions about how they meet their tax obligations. In Spain, you are required to keep evidence of your business expenses. In case an expense management tool received a certification from the Spanish public administration organisation, these records of business expenses may be stored digitally. In the following articles, we will discuss the digital storage of records of business expenses, as well as mileage and per diems.