How can I get my grandson social security number

[lewismaia779]

His mom refused to give us his social security number

[Bsch4477]

Lacking any documents which would have his SSN you would have to contact Social Security to ask how to prove you are entitled to have it. 

[xmasbaby0]

You do not say why you want or need your grandchild's SSN.  If you have claimed your grandchild as a dependent on a previous tax return, then the SSN will be on that past year Form 1040.  

 As Champ @Bsch4477 replied above, you would have to show Social Security some proof or a reason to share that information with you if your son/daughter will not tell you the child's SSN.   Are you trying to claim the child as a dependent on your own tax return?  

https://www.ssa.gov