Territory Management default record access
Key Takeaway
Territory defaults set the starting access to accounts, leads, and opportunities. Set the access to child territories' opportunities to view and edit so that parent territory users can edit those opportunities. Users in the child territories keep their own, lower level.
Default record access for territories sets how users can view and change the records tied to the sales territories you set up. You set these defaults once on the Territory Settings page. Each territory uses them unless you give that territory its own access levels. The territory hierarchy also affects access, because a territory's access level is inherited by the territories above it.
What the defaults control
Default access settings control how users can access and modify records associated with your territories. The standard settings cover accounts, leads, and opportunities. Access levels include view and view and edit.
If you use Private default internal access for contacts or cases, you can also set territory access for those records. The contacts and cases options don't apply in every org.