From their website:
"For extra peace of mind, we offer consequential loss compensation for financial loss due to delay, loss or damage to Special Delivery 9.00am or Special Delivery Next Day items.
So for example, if an urgent passport application is lost or delayed, preventing you from going on your pre-arranged trip, you can claim the travel cost from the Passport Office, who issued you with the passport.
You can apply for consequential loss compensation if you're using Special Delivery for any UK destination, except the Channel Islands, Isle of Man or HM Forces addresses."