The phrase "variable income" means that the amount of money someone earns can change or vary from one time period to another. It is not the same fixed amount received regularly, but can be more or less depending on different factors. Full definition
Managing credit cards, auto loans and other debt can be challenging, especially for those with variable income streams because of bonuses or commissions. (nextgenfinancialplanning.com)
Can I afford another monthly bill on variable income? (policygenius.com)
We've got a really variable income stream, so for us budgeting is what works the best. (affordanything.com)