I added my childs w2 on my tax return but it wont let me change the social security number.

[DianeW777 · Accepted solution]

It cannot be changed. Your child's W-2 is not reported on your tax return.  The income, as well as any withholding, will be attached to your child's social security number (SSN).  

File a return for your child if the meet the filing requirement or if they have any withholding that should be refunded.

Filing Requirements for Dependents: IRS Publication 501

• IRS Publication 501  (See page 4 for filing requirements for dependents.

Single dependents—

• Were you either age 65 or older or blind? No. 
• You must file a return if any of the following apply. 
  1.  Your unearned income was more than $1,250. (Form 1099-R)
  2.  Your earned income was more than $13,850. 
  3.  Your gross income was more than the larger of: 
     1. $1,250, or 
     2. Your earned income (up to $13,450) plus $400.