My taxes keep getting rejected because of this error SEIC-F1040-506-03 and I'm not sure why or how because no one else has claimed my child. How do I fix this?

[xmasbaby0]

Someone might have inadvertently used a wrong SSN and put your child's SSN into the system.  You cannot overcome a duplicate SSN rejection.   If the IRS is rejecting your e-file due to a duplicate SSN, the only way you can file is by mail.  Sorry.

Print, sign and date the return in ink, and mail it.

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

[ee-ea]

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/fix-e-file-reject-seic-f1040-...

[DoninGA]

Verify that you entered the dependent's name and Social Security number exactly as it is entered on the dependent's Social Security card.

If it is correct and the IRS continues to reject the tax return then you will have to print and mail the return.

See this TurboTax support FAQ for how to print a tax return for mailing when using the online editions - https://ttlc.intuit.com/turbotax-support/en-us/help-article/printers-printing/print-mail-return-turb...