How to design database in order to store "default" items

I'm developing an app in Laravel. I've models called Account and ShippingAddress. An Account may have one or more ShippingAddress, but a ShippingAddress can only have one Account. So that I'm using a one-to-many relation.

Now I want to implement a functionality that marks a ShippingAddress as "default", and there's can be only one "default Shipping Address" per "Account". I've identified two possible solutions:

1. Add a "is_default" column on ShippingAddress table.
2. Create a "default_shipping_address" pivot table where I'll store the "account_id" "and shipping_address_id".

Which one is the best solution up to you and why? In case of the second one: how can I implement a one-to-one relation in Laravel through a pivot table?

via Chebli Mohamed