I recently returned from the United States and discovered that I still had the little card from immigration inside my passport. I believe this is meant to be handed in to your airline at the check-in counter when you leave America, but I’m not sure. Usually I do hand it in. I go to the US on holiday often and am worried that I might be in trouble next time. What’s the situation on this? I know the immigration officials are tough over there. J Smith, London W5

When leaving the United States you are required to hand in the I-94 or I-94W forms, normally stapled to your passport, to your airline check-in desk. Doing so ensures that your exit from the country is logged.

If you don’t – and on rare occasions this does happen, usually because of an oversight on the part of airline staff – officials may assume that you have overstayed your tourist visa when you return for a trip to the US.

You need to fill in your departure details on the form, and send this, along with a covering letter and evidence of your departure (such as a boarding card), to ACS-USCIS, SBU, PO Box 7125, London, Kentucky, KY 40742-7125, USA. Keep a photocopy of all the documents. See www.usembassy.org.uk for further information.

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