can a user edit their order?

I need for a user to be able to go into their account and to their order and be able to edit it after they have placed an order.
Is this possible?

Particularly the custom order fields is what I need them to be able to go back into as they are unlikely to know the answers when they place the order.

For example, one of the custom fields is asking them what car rental company they will be using during their stay, but they might not know that when placing the order, but should have the ability to update that once they find out.

thank you