There may be income tax issues to resolve, such as, whether you will file joint tax returns during your separation, who will take the dependency exemption for the children in the event you file separately, who will pay any penalties and interest in the event of an audit or
previously filed joint returns, who will receive any tax refunds that may be due, etc..
If you and your spouse agree, you can amend your
previously -
filed separate
returns to a single
joint return up to 3 years after the original tax deadline (this does not include extensions).