Collapse rarely used address fields

When to use it

When checkout shows 'Address line 2', 'Company' or 'Delivery instructions' open by default though few buyers use them.

How to run it

Hide each behind a small '+ Add apartment or company' link that shows the field only when clicked.

Why it works

Make the action easier to complete

Every visible field adds effort and one more place to make an error. Baymard explicitly recommends hiding Address Line 2 and Company behind links, which moves checkout closer to the ~12-element ideal.

Source: Baymard Institute