Your car IU number is a 10-digit number located on a sticker on your in-vehicle unit and can also be found in your vehicle's log card.

To access your vehicle's log card, simply login to One Motoring website with your Singpass, select 'Vehicle Hub', 'Enquire & print vehicle registration details', select the vehicle registration number of the required vehicle!

Find out more here: https://www.motorist.sg/article/524/everything-you-need-to-know-about-your-in-vehicle-unit-iu