Hello Rob:

I don't mean to sound like I am giving you a hard time (that is not my intention at all), but, I think you are missing the point.

An IDP is nothing more than a translation into multiple languages of a driver licence. By itself, it confers no privileges. An IDP exists for the sole purpose of enabling people in foreign countries to see what type of vehicle you are allowed to drive according to your home country driver licence, and to see that information in about 6 different languages. An IDP has no validity in the home country of the holder.

IDPs were first issued in 1926. Today, they are about as useful as traveller's cheques, which is to say that yes, IDPs still exist, and yes, if you want to be very very careful when travelling in strange and exotic countries, you should probably carry one. I carry one, because I travel in a lot of very exotic countries (about 60 different ones a year before I retired in 2013, now, only about 15 different ones each year). But, the last time I actually needed to pull it out and present it was in Angola back in 1990.

The main point - so far as the insurance issue is concerned - is that without an underlying national licence (which one is, in theory, obligated to present for inspection along with the IDP), the IDP is worthless.

For that reason, I have a very hard time believing that an insurance company from the rider's home country would refuse to honour a claim from a person who was operating a motor vehicle while possessing a valid national driver licence from their home country. It's simply not an issue for the insurance company... the only issue for them is whether the driver was properly licenced to begin with, which implies the underlying national licence, not the IDP.

This Wikipedia page explains the whole thing in great detail: Click Here.

Michael