This is a US question. If a married couple have a primary residence in one state (say Florida with no Income Tax) and another vacation residence in another state (say Mass) and while being on vacation there (MASS) one of them works at a local store and earns a few hundred dollars for which the store sends a W2, what are their Tax liabilities?
Note the income in Mass was very small but the couple's income in Florida was > 50K $. Do the couple even have to file anything in MA? The amount earned in MA was well below the minimum required to file and only MA primary residents are required to file.