I don't know what you are asking. You can certainly call the other parent. I doubt that the other parent's tax preparer would take a call from you.
If your return is correct, file by mail and let the IRS sort it out. However, make sure your return is correct.
Only the parent who has custody more than half the nights of the year can automatically claim the child. The other parent can only claim a child with the custodial parent gives them a signed form 8332, or they have a custody order from a court signed before 2009. If you are the custodial parent and you aren't required to share the dependent this year, just claim your children and mail your return. If you are trying to allow the other parent to claim one or more children, you have to indicate the child lived with you more than half the year (pick "7 months" or longer) and you are letting the other parent claim the child with a form 8332. Don't forget to mail the signed form to the other parent.
If you are not the parent who has custody more than half the nights, you can't claim anything unless you have a signed release from the other parent or a pre-2009 custody order. Even then, you must answer that the child lived in your home less than half the year (choose "5 months" or less) and you are only claiming the child with a form 8332. This will qualify you for the child credit but not EIC or head of household--those benefits always stay with the parent with majority custody and can't be shared or transferred. Claiming the child lived with you all year so you can claim the dependent without the form is one way to cause an e-file conflict.
If you have the right to claim a dependent claimed by someone else, then you must print and mail your return if you are not the first one that files. The first one that files with your child will be able to e-file. The second return will be rejected and must be mailed in.
- The IRS will process your return and pay your refund if you are entitled to one.
- Later, they will contact you and the other taxpayer to determine who is entitled to claim the dependent. (The IRS is not allowed to tell you the identity of the other filer.)
- The taxpayer who incorrectly claimed the dependent will be assessed any additional taxes and penalties, and required to file an amended return