And even then it pays to check the small print carrying goods owned by another company / employer may not be covered by a standard business use policy or be specifcally excluded as it may be looked on as carrying goods for "hire or reward" which would need a goods in transit endorsement.
I had this issue a number of years ago we did a lot of installation work for a comms company and would quite often be carrying their kit / goods to site to install and found that standard business use cover didn't fully cover us
With insurance it pays to check EXACTLY what the cover you have covers you for and not wait until you need to make a claim and find the insurance company wriggling out of paying also make sure you have all the details in writing
On a side note we had a job about 25 years ago that needed us to take one of our vehicles airside at a midlands airport the client required us to have third party insurance cover of £20m to do this, after an interesting conversation with our broker we were quoted £1000 for 3 days cover as an extension to the normal vehicle policy