Only Internal users are counted towards your pricing plan. This means any user who is active within your account and has an internal role counts towards your Project.co pricing plan.
It’s common for internal users to include you, your team and any freelancers or contractors that you invite to work as part of your team on projects.
If you would like to add a freelancer to your internal team to work on a temporary basis then you can invite them and then remove them when their work is complete. When you remove them from your account your internal team will reduce by 1 user but their contributions to projects such as comments and files will remain on each project. See deactivating internal users for more info on this.