Correct Employer Matches with True Up Conributions.

Solo 401k

 When employers match employee deferrals each payroll throughout the year, each employer contribution is based on the participant deferral for that payroll. 

Any contribution changes an employee makes during the year could change the match amount, even if the  contributions are enough to receive the full amount that year. 

The true-up match additional contribution is how the employer's contributions are adjusted out so participants receive the accurate value from the employer match.

Solo 401k Plan: Your Opportunity for Checkbook Control of Your Future