Legal Question in Family Law in Washington

Legal separation is different than date of separation.

I agree with what Mr. Baner wrote and would add the following. For purposes of taking out loans or incurring any liabilities, anything that happens after the date of separation, will be treated as if you were legally separated.

However, being "legally separated" is a legal term of art, referring to people who are still married, but aside from that legal relationship to each other, generally live completely separate lives. It's pretty rare to see people seeking legal separation these, days. In my experience, the majority of those that do this, do so for religious or cultural reasons.