I don't know about the U.S. but some Canadian insurance companies are refusing to pay claims when their insured has an accident in a foreign country if the do NOT have an I.D.P. which is an international permit honoured by most countries in the world. The attitude of the insurance companies is that, even though the country you're in may accept your driver's licence, it is not a valid permit for that country - but - an IDP...International Driver's Permit IS . They are available from CAA or AAA for around $30 and are a good investment.