While most of these forms should be provided to you by Jan. 31 (and they may also be available online), K-1s aren’t due until the 15th day of the third month after the end of the entity’s tax year. For example, if it uses the calendar year as its tax year, you might not receive a K-1 until March 15.Schedule K-1 for your share of the income and deductions from any pass-through, or flow-through, entity , such as a partnershipIn addition to money from employment, known in tax parlance as “ earned income ,” you ...