Has the Custodial parent signed it?
If you are filing your return
electronically, you must file Form 8332
with Form 8453, U.S. Individual Income
Tax Transmittal for an IRS e-file Return. If you are filing your tax return using an online provider,
mail Form 8453 to the IRS within 3 business days after
you have received acknowledgement from your
intermediate service provider and/or transmitter that the
IRS has accepted your electronically filed tax return.
Mail Form 8453 to:
Internal Revenue Service
Attn: Shipping and Receiving, 0254
Receipt and Control Branch
Austin, TX 73344-0254
https://www.irs.gov/pub/irs-pdf/f8453.pdf
