Discuss the legal separation with your spouse. If he agrees to it, you may both sign the paperwork. If he does not agree, you can file on your own.
Determine where you will file the paperwork. One or both of you must have lived in Colorado for at least 90 days before filing. If you and your spouse live in two different counties, you may file in either one. If you both live in the same county or only one of you is a Colorado resident, file in that county.
Obtain the forms needed for your case from the Colorado State Courts website. Click on the "Forms" tab, then choose "Domestic/Family" forms. Click on either "Dissolution - Legal Separation WITH Children" or "Dissolution - Legal Separation NO Children," depending on your family situation. The web page that opens will contain only the forms that you need for your type of case.
Download the forms you need to start your case. Whether or not you have children, you need a Case Information form, a Petition for Dissolution of Marriage or Legal Separation, and a Summons for Dissolution of Marriage or Legal Separation.
Download the forms and fill them in using black pen. Be sure to check the "legal separation" option wherever you are asked about the nature of the case. Answer all questions fully and honestly.
Review the documents carefully to ensure that you have filled them out correctly. If you need to make any minor changes, cross out your answer, fill in the correct information and initial it.
Sign the petition in front of a notary. If you and your spouse are filing together, he must also sign the petition in front of a notary.
Take the original documents to the clerk at the county courthouse. Bring one copy of the petition with you also.
Pay the filing fee. Fees may vary among the counties.
Make a copy of the file-stamped petition. If the clerk gives you any other documents, make a copy of each of those documents as well.
Notify your spouse that the case has been filed. If he signed it with you, simply give him a copy of the petition and ask him to file a notarized copy of the Waiver and Acceptance of Service at the courthouse. If you filed the petition by yourself, you must have your spouse served. Make arrangements with a sheriff, process-server or someone over the age of 18 not involved in the case to serve him. Your spouse must file a response within 21 days if he was served in Colorado, or within 35 days if he is served somewhere else.