I am not licensed to practice in Virginia, but I do know that, if you are seeking a divorce on the grounds that you have spent 6 months apart, the parties need to have a signed agreement. Otherwise, you need to wait the entire 12 month period and not have lived together during that time.
I hope this helps.
No, you cannot file without it.
One must be separated for 12 months to file for divorce on "no-fault" grounds. However, where the parties have entered into a separation agreement and there are no minor children, then the separation period is reduced to 6 months.
So, there are two prerequisites to the six-month divorce: an agreement and no minor children.
Agreements must be in writing and signed by both parties. If he has not signed, you have no agreement. No agreement, no divorce.
After 12 months of separation, you can file without an agreement. He may likely sign at that point as there is nothing he can do to prevent you from proceeding.
Since the two prior attorneys have answered your question, I would just advise you that you can get a free book "What Every Virginia Women Should Know About Divorce" which outlines the process and might answer other questions as well.
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