When it comes to checkout, OpenCart provides a way for your customers to specify different addresses for delivery and billing. Some may consider it a fraud risk to separate addresses and would rather let buyers specify a single address only.
OpenCart doesn't allow doing it by default. However, we've developed a simple and free module to do it.
UPDATED on 10/05/2016: OpenCart 2.x version is now available!
This is a free vQmod that removes step 3 (delivery details) on the checkout page. It is a one-file vQmod addon so you need vQmod installed. However, if you don't want to use vQmod, you can modify your core files according to the xml file - it only introduces a couple of changes.
This module doesn't remove shipping as such, it just makes it impossible for customers to choose different addresses for billing and delivery. The reason for that is that some consider it a fraud risk to separate addresses.
You can download the file here: [wpdm_file id=4]