How do i find out which dependents social security number has already been filed

My return was rejected due to one dependent being already claimed. It does not say which dependent. How do I find out which one it is?

Privacy Settings

We provide you with a way to opt-out of advertising activities on our websites

Third Party Advertising Vendors

We leverage outside service providers who assist us with our marketing and advertising activities. Note: by opting-out of this tracking, you may still see Intuit advertisements, but they may not be tailored to your interests.