I don't have any personal experience, but a quick web search uncovered the following information:

http://www.consular.canada.usembassy.gov/form_i-94.asp

What If No One Takes Your I-94 Form Upon Departure

Failure to turn in your I-94 (or I-94W) when you leave the U.S. can create a serious problem. Without this record of your departure, you will be identified in our records as an "overstay." Being identified as an overstay means that you will be denied re-entry into the U.S. If you failed to turn in your I-94, please send it - along with any documentation that proves you left the U.S. to ACS Inc. 1084 South Laurel Rd., London, Kentucky 40744.

Documentation to prove your departure can include the boarding pass from your flight. If you exited the country by a land border it is much harder to verify that you did- in fact - leave the country on the date you claim. If you have any documentation of your arrival in your home country (i.e. passport stamp), then you should send a copy of that. If the above office does not have any supporting documents to substantiate your claim to have left the U.S. on a certain date, there is no guarantee that you will be entered into the record as having done so. We strongly urge you to keep a copy of what you send to ACS Inc. and to carry it with you the next time you come to the U.S. in case the CBP officer has any questions about your eligibility to enter.

If you want to confirm that your I-94 was received by ACS, please give them 4 months to process the paperwork. Then you can write the following address to determine whether or not your departure was recorded. If you turned in the I-94 when you left the U.S. as required, please do NOT request confirmation that it is on file. This process is only for people who did not turn in the I-94 when they exited the U.S.

You will need to provide your name, date of birth, passport number, and date of departure, in addition to asking whether or not your departure was recorded. U.S. Customs and Border Protection Air Sea Passenger Operations, Room 5.4D, 1300 Pennsylvania Ave., N.W., Washington D.C. 20229.

In addition, the next time you enter the U.S. it is recommended that you carry with you evidence of your previous timely departure.

Definitely follow those DHS instructions for returning your documentation along with proof that you left the country. I have personally witnessed people attempting to re-enter the US many years after failing to turn in an I-94. It is not a pretty sight. If you take care of the paperwork now, you'll save yourself loads of trouble in the future.

Most of this thread is about Canadian citizens working or studying on visas. The OP is a citizen of a VWP country, who (presumably) entered the US as a tourist. For that group the I-94 is obsolescent - ESTA is mandatory, and is supposed to supersede the I-94 at some (ever receding) future point.

If the OP had ESTA, and flew LGA-YUL, then the DHS is aware s/he left the country. It's definitely a good idea to deal with the I-94, but I don't believe it will be difficult to resolve the issue, and there's no reason to panic about it.

FWIW, I'm a Canada-based EU citizen, and I've often left the US with the I-94 in my passport - they're very bad about taking it on the US side, and it happens all the time. Occasionally I've even had to insist they take it. When I have forgotten to deal with it I've always been able to sort it out with the CBSA on arrival, or with the agent the next time I check-in for an international flight.

I'm glad you've had good experiences, antirealist, but I have definitely witnessed people of various citizenships (including non-Canadians) suffer terrible consequences after having failed to return an I-94. I'd take care of the problem now, before the next trip to the US, rather than risk an adverse event upon next attempted re-entry.

Incidentally, I often have a multi-entry I-94 in my passport, and I face the opposite problem: over-eager gate-agents who remove the I-94 from my passport even though it needs to stay there. On one occasion, a gate agent removed my husband's I-94, and my husband threatened that he refused to board the plane unless the gate agent returned his I-94. I could only chuckle! I mean, why would the gate agent care whether or not my husband boarded the plane?! The crew would gladly have left without him onboard! After the intensity of the discussion was brought down a notch, the I-94 was returned, and everyone continued along their merry ways.

Also..just as an FYI for anyone flying USair..

Canadians arriving INTL (not transborder) into CLT (..and only in CLT..some local station decision, apparently) need to fill out an I-94..so make sure you get one on the plane..

I actually do have personal experience with this situation. Since the introduction of APIS and ESTA it's no longer as serious a problem as it used to be, but nevertheless you should follow the instructions on the DHS website referenced above. And don't panic, it happens a lot.

If it's not already clear, the green I-94 for VWP visitors is not the same document as the white I-94 that visa holders have.

My friend is just working on that problem right now. CBSA hardly collects the I-94 at land crossings because they anticipate people to go back to the US again. In the past he will just send the I-94 back to the US Consulate here in Canada. But now its all changed - he got a letter with the following:

Dear Sir/Madam

Re: I94 Arrival / Departure Record

8. Other: Please refere to the information or instrucutions at the back regarding returning your I-94 (white or green) Arrival/Departure record.

The US DHS announces that, if you left the US with your Arrival/Departure Record (I94 white or green) still in your passport, your departure was not recorded. It is your responsibility to provide the DHS sufficient information to properly record your timely departure from the US.

If you do not show a timely departure from the US, or if you cannot reasonably do so when you next seek entry into the US, DHS may conclude you remained in the US beyond your authorized stay. If so, our visa may be cancelled, your entry into the US may be barred and you may be returned to your foreign point of origin.

To show your departure, DHS will consider a variety of information, including, but not limited to:

- Original I-94 (white or green)
- Original boarding passes that you used to depart the US
- Photocopies of your entry or departure stamps in your passport indicating entry to another country after you departed the US (copy all passport pages that are not completely blank and include the biographical page containing your photograph)
- Photocopies of other supporting evidence that shows your name / departure date, to indicate you were in another country after leaving the US, such as:
> Dated pay slips or vouchers from your employers outside the US
> Dated finanical records showing transactions outside the US
> School records showing attendance outside the US
> Dated credit card receipts, with the credit card number deleted, for purchases made outside the US

Your statement alone, without supporting evidence, is insufficient. If you send original materials, please retain a copy since DHS cannot return original materials after processing. To help correct your records quickly, please include a signed, dated explaination in English.

Please mail your explanation and supporting documents to the following address:

ACS-INU SBU
PO Box 7125
London, KY 40742-7125
USA

Do not mail your I94 or supporting documents to any US Consulate or Embassy, any other DHS office or to any addres other than the one stated above. Only at this location can DHS make te necessary corrections to your records to prevent serious disruption to your US travel in the future.

Canadians arriving international to the US are required to fill in US Customs Declaration Card CBP Form 6059B only.

Canadians with F-1 status or work permit are required to fill in I-94.

Permanent Residents are required to fill in I-94 or I-94W depending on where their foreign passport.

I flew enough SIN-SFO/EWR to know which forms to fill......

One more note - If the I-94 expiry date have not passed, you can return to the US again using the same I-94! That is why many agents do not take away the I-94 cards - because its contingent on expiry not definite departure!

There's a FAQ on US CBP's web site that deals with this. It appears that since the OP left the US by air (LGA-YUL), there's no need to mail in the I-94, since they can verify the departure based on the flight manifest. However, if the OP had driven from New York to Montreal and then flown to Europe from there, he would have to mail in documentation:

https://help.cbp.gov/cgi-bin/customs...i=&p_topview=1

If you returned home with your Form I-94 (white) or Form I-94W (green) Departure Record in your passport, it is possible that your departure was not recorded properly.

If you departed by a commercial air or sea carrier (airlines or cruise ships), your departure from the U.S. can be independently verified, and it is not necessary to take any further action, although holding on to your outbound (from the U.S.) boarding pass - if you still have it - can help expedite your reentry next time you come back to the United States.

If you departed by land, private vessel or private plane, you will need to take steps to correct the record. If you do not validate your timely departure from the United States, or, if you cannot reasonably prove you departed within the time frame given to you when you entered, the next time you apply for admission to the U.S., Customs and Border Protection (CBP) may conclude you remained in the U.S. beyond your authorized stay. If this happens, your visa may be subject to cancellation or you may be returned immediately to your foreign point of origin.

I have a blank I-94 lying around home.... this is what it says on the back of the card:

IMPORTANT: Retain this permit in your possession; you must surrender it when you leave the US. Failure to do so may delay your entry into the US in the future. You are authorized to stay in the US only until the date written on this form. To remain past this date, without permission from DHS authorities, is a violation of the law.

Surender this permit when you leave the US:
- By sea or air, to the transportation line;
- Across the Canadian border, to a Canadian official;
- Across the Mexican border, to a US official.

Students planning to reenter the US within 30 days to return to the same school, see "Arrival-Departure" on page 2 of Form I-20 prior to surrendering this permit.

With airlines, they do have the capabilities to track when you left the country....but whether they do so proactively or want you to prove to them is another story.

Thanks everyone!

As you all can see there is no clear procedure here. The US governmental sites are contradictive in the way that one says "no problem" but the other one says "problem". At the same time one says to send in the original boarding pass to London, KY while the other one says to hold on to it until the next re-entry to US. The only common thing is that you are not allowed to neither call nor ask for status..

I'll see what I will do.

My experience with an F-1: If I'm travelling between Canada/US/Mexico, stays in the passport.

Any time I go outside of NAFTA, I have to fill out a new one. Makes no sense because the original I-94 is directly written onto my SEVIS (my de facto "visa"), but I don't have that anymore.

I see a lot of "Canadian Citizens don't need to fill out an I-94 for such and such visits" in this thread however this is just simply not completely true and misleading. I think if you're not sure of what you're talking about it's best not to answer to such questions and cause confusion.

Certain Canadian Citizens who were born in certain countries (fill in with the usual suspects) need to fill out a new I-94 every single time they enter the U.S. for any purpose including transit, whether or not the previous I-94 expired or not. Failure to surrender the I-94 at departure and/or to follow the exit registration can cause serious problems for re-entry the following times.

Have a notarized copy made and send it to London KY along with a letter explaining that you are holding on to the original to present upon your next re-entry.

i recall hearing that........ sad..... last time i had a friend that came to visit me from BUF for the wkend and ended up detained for 3 hours.