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They can be sent together, or separately, as the IDOC instructions indicate. I did mine together… I had my dad (non-custodial parent) mail me his tax info, which he did, and I just added it to my parents’ packet. None of them saw the others’ information.</p>
<p>I just didn’t want to risk anything getting lost or misplaced by sending in two packets, as it seems like a very controlled, strict process (receiving the documentation, that is).</p>