I thought this would be easy to find, but no luck so far: Are there specific guidelines on the timeliness of self-employment data? I am doing a 433A for a client who has a schedule C and a rental schedule E on her 2018 1040. Do I just use last year’s annualized numbers? Or do I need to get updated information to see if those numbers are a realistic estimate so far for this year. She is a realtor and her schedule C can change drastically from one year to the next.