Both my children claimed themselves as dependent. Can I also claim them and amend their returns later?

[Cindy0H]

If you try to claim them, your return will be rejected and you will have to file by mail. That being said, you can do so and also have them each amend their returns. This will prolong the process for a refund if there is one.

[Hal_Al]

You do not have to wait for their amended returns to be processed, or even filed, for you to claim them. You can file now. You just have to file on paper. Your refund will take the normal 6-8 weeks for a paper return.