It depends on the type of wages he or she has. If it is employment income reported on form W-2, then the filing threshold is $6,300. However, if it is self employment then the filing threshold is $400. However, there are different filing limits for unearned income. Please view the Turbo Tax FAQ below for more information on filing requirements for dependents.
https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Tax-Filing-Requirements-for-Children/I...