I have never been asked for an International Drivers Permit from a rental car company. They are not interested in it.
I was, however, once berated by a policeman from Maryland for not having one. It is my understanding that there is no requirements to have one when driving in the USA. A valid Australian drivers licence is sufficient. However, when driving south on I95 just before the Baltimore Tunnel I was pulled over in an Avis rental car. The registration sticker on the numberplate had expired the previous day (it was the 2nd day of the new month) and I had no idea I was driving a vehicle with an expired sticker.
The office obviously wanted to see my licence etc. He took a while to walk to my car, so I assume had already done a rego check on the vehicle so probably already knew it was a rental.
I showed him my Aussie (Qld) licence and the rental papers from Avis. The papers showed that the rental agreement covered the period over which the sticker would expire - I had not extended the rental or failed to return it before it expired etc.
Anyway, he looks at my licence and say "what's that?". I told him it was my Queensland Drivers Licence. He says the only valid licence for driving in the USA is one issued by one of the 52 US states, or Canada or Mexico. When I said that an International Drivers Permit was not a requirement for driving in the USA, he was adamant I was wrong and he was correct.
Anyway, he threatened to arrest me for driving an unregistered vehicle and to impound the car. He asked me about what I was doing in the USA and why I was driving south on I95. I explained I was returning to DC after a few days in Delaware and was due to return the rental car to Dulles airport the next day when I was flying back to Australia via LAX. Back then I had a paper ticket and showed him my ticket to fly IAD-LAX and then LAX-BNE the following day, along with my Australian Passport as a means of identification (since he would not recognise my Aussie drivers licence).
Anyway, after he looked all through my paperwork, and was satisfied that I had not stolen the vehicle and that it was Avis's fault for renting me a vehicle whose registration would expire during the rental period, he let me go with instructions to drive straight to my hotel and then to the airport tomorrow and tell Avis about the expired sticker.
I still believe I was right and he was wrong regarding the need to have an International Drivers Permit to drive in the USA. However, I now always carry one with me and claim the cost of it back on my company travel expenses. Its easier to have one and not need it, than to argue with an uninformed police officer on the side of I95.
In some ways it may have been interesting if he had arrested me. It would have been a very interesting phone call to Avis asking them to come bail me out as they had rented me a vehicle that would be illegal to drive before the end of the rental agreement. And it would have been interesting to get an apology from the arresting policeman when he did his research and found that he was wrong regarding the IDP. But at the time I did not need the excitement and was very happy to just be polite and agree to comply with the officer's requests.
On my last IDP, the person who issued it forgot to put the date on the front cover. So one day I might get around to writing a date on it. Its going to be the longest 12 month validity I have had
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