What changed
Qualified tips are deductible up to $25,000 a year, and the deduction shrinks once modified AGI passes the limit (over $150,000 ($300,000 joint)). It is a below-the-line deduction claimed on the new Schedule 1-A, so a client who takes the standard deduction still gets it.
A self-employed client cannot deduct more than the net income of the business where the tips were earned. Anyone working in a specified service trade or business, the same list used for the QBI deduction, does not qualify at all.