Technically… no, you don’t need a separation agreement in order to get divorced. You can set out your agreements in your divorce application, but it can get extremely complicated to do so if you don’t have all the details worked out. In an agreement, usually the items set out include some or all of: a parenting plan, child support, spousal support, and division of property.
A separation agreement can be in many forms – sometimes you need a lawyer to draft the agreement to make it final and legally binding, and sometimes you can do it yourself with a witness. Talk to a lawyer to determine your particular needs.
If you have children, the separation agreement becomes a detailed parenting plan by which you and the other parent govern yourselves. The level of detail, the wording, and the nuance of a separation agreement may be quite different than that of a divorce judgment. In an agreement, you and the other parent set out your “code of conduct” for how you will parent your children. The parenting plan portion of your agreement can be as much as 20 pages or more. The more detail, the less likelihood for conflict into the future, which is what most people want – for the conflict to stop / be reduced, and to be able to parent your children in your own home according to the plan set out, without interference by the other party.
On another note, such things as spousal support can be more carefully laid out in an agreement. Spousal support is a complicated area, especially in the area of court applications to vary the amount of support you are receiving. In agreements, lawyers can very carefully craft the wording to create parameters around the ability to bring future court applications.
Don’t short-change yourself. You’ll thank yourself later.