The expanded Child Tax Credit in 2021 was generous but suffered from low take-up among the lowest income families. We identify families who are likely eligible and experimentally helped them file taxes through VITA, the volunteer income tax assistance program. Preliminary results suggest that the assistance intervention nearly tripled the rate of filing through VITA but did not increase overall filing rates. This trial is registered in the AEA RCT registry (https://www.socialscienceregistry.org/trials/8860).