The following is a FAQ entry on the US Department of State website A related question without an expicit answer in the State Department FAQs is: What if it is a Sunday, you are at the airport about to take a flight to return to the US within 2 hours and you find out that you have lost your passport? That is precisely what happened to me on July 6 as I was about to return to JFK from HKG through SFO on UA. (the following narrative is rather long. While I tried to proof it as well I could, I am sure that there will be typos, grammatical errors, omitted words, and more...) After 8 wonderful days in HKG, I took a cab from Conrad HKG for the airport at 8:30 am on Sunday, July 6, for an 11:00 am UA flight to SFO. I had a carry-on bag, which was put in the trunk. I also had a backpack and a long tube containing a 3ftx5ft poster, which I had just presented at a conference at HK University of Science and Technology -- the real purpose of the trip. After an easy ride, since it was a Sunday morning, we arrived at the airport shortly after 9:00am. I pulled out my wallet, paid the cab fare with my remaining HK$. This is where I got in trouble; I tried to multi-task! The cab driver handed me the receipt for the cab fare and some change, at the same time I was reaching for my poster tube and backpack. With so many things in my hands I needed to put some things down. Rather than putting my wallet back into my pants back pocket, I put it on the backseat of the cab, intent on putting the change and the receipt from the driver in it. I then picked up the poster tube and backpack and got out of the cab. The taxi driver had retrieved my carry-on from the trunk and was handing it to me so I grabbed it, and put it beside the backpack and poster tube. Meanwhile, my wallet was still on the backseat in the cab, briefly forgotten... The driver got back into his cab, waved goodbye and drove off. About 30 sec later, I knew that something was very wrong and I immediately realized what it was. My wallet was on the backseat of the cab, which just left! If all I had in it had been money and credit cards, I would not have cared very much. I did have 11 credit cards and one debit card, but the trouble was that my passport, along with my other forms of ID, were also in the wallet!!! All panicky, I stopped the next cab I saw and frantically explained to the driver that I urgently needed to go after a taxi which had just left with my wallet. He could be fined for picking me up on the departure side of the terminal, but he understood my desperation and let me in. I tossed in my stuff on the back seat and we raced in the direction that the other taxi had headed. It was, of course, a Quixotic quest because, like in any big city, there are lots and lots of cabs that look alike in HKG, and the cab that we were after could have gone in any direction, including just going to the arrival queue to pick up a fare before going back to the city. So, after about 10 min on what was clearly a wild goose chase, I asked the cab driver to take me back to the airport . This brief ride would cost me about HK$200, which was almost exactly all the money that I had gotten in change from the other driver and had put in my shirt pocket. This meant that, in addition to not having my CCs and debit card, I was totally penniless! I went inside the terminal and found the UA check-in counter, where I explained to the agent that I had just left my wallet, passport, other forms of IDs, and credit cards in a taxi. The agent's advice was that I should report the loss immediately to the airport police. I found the airport police station in which there was an agent/cop, who did not seem to be in a hurry to do anything. He was on the phone and made me wait for at least 15 min. Tick...tock... One of the things that I thought would help out of the jam was the receipt that I had gotten from the cab driver, which I had also put in my shirt pocket, because it had the cab medallion number. I explained the situation to the airport cop after he got off the phone and I handed him the receipt with the cab number. He called around the airport to find out if anyone had seen the taxi (caught on a CC TV?) or if it had entered into one of the airport cab queues. Zilch. From the cab number, the cop was able to get the cab owner's phone number, and called him. No answer. They would keep trying to reach him until I left the area, but no one picked up. My one hope for a quick resolution did not pan out... Meanwhile, I needed to get an official police report of the incident in order to be able to document that I had reported the passport lost. The cop asked me if I had any other form of ID, I was not sure. I had my backpack with me so I told him that I would check. I had my business/loyalty card organizer that contained my hotel and airline elite status cards, department store cards, etc... but nothing with my picture that could be considered a valid ID. Then I looked in all the pockets of the backpack and there it was! For whatever reason, I had put in one of the pockets of my backpack my old passport. I had replaced it in December 2013 because it had run out of visas pages. My finding that old passport would save the day... It was getting almost time to board the plane so the UA agent I had spoken with at the counter came into the police station to see how I was doing and to let me know that unless I had some form of "valid" ID, she did not think that I would be able to clear HKG immigration. I told her that I had just found my old passport, which she then requested to try to find out whether I would be able to clear passport control with an expired passport. By this time, I was eager to wrap up things up with the cop, get a copy of the police report and leave. But the guy was taking his time. He wanted a detailed list of everything that was in my wallet, which I was able to provide, including providing the number of the new passport that was just lost (I religiously memorize my passport numbers), all of which went on the report. The UA agent meanwhile came back with partial good news. She had contacted the crew of the UA 744 that was to fly me back to the US, told them about my losing my passport and about my having my old one, and asked them whether they would let me board with it. The crew said, fine; he is a US citizen. We'll take him back and let him deal with the Customs and Border Protection (CBP) agents at SFO. I preferred that to staying in HKG with no money! At this point, the great unknown was whether the HKG immigration would let me through with my old passport. The UA agent said she'd also contacted them, and they said that I should just go through security check and then get to a passport control booth to speak with an agent. The UA agent leading the way, we cut through the long line of people in front of us and got to the passport control booth, where I handed my police report to the agent, and explained that I had just reported my passport lost. I also handed him my old passport. He took the documents, and called a supervisor, who took the documents and disappeared in a back office. Tick...tock.. About 15 minutes later, the immigration supervisor returned, handed the documents back to the booth agent and said something to him. The booth agent then called me back to the booth and told me that I could go through. Big Sigh of Relief!!! In the mean time, the UA agent, who by now was like my shadow because she was with me every step of the way, informed me that the 744 had finished boarding, so we had to hurry. She took my poster tube, which was long and slowing me down, and we took off running. Those who have been at HKG would know that the international departure gates are quite far away from security check. When we finally made it to the gate, I was completely drench with sweat. I boarded the plane following a brief inspection; my upgrade to business class had cleared, thankfully. I went straight to my seat, sank in and asked for a large ice cold coke. I had just dodged a bullet because had I stayed in HKG, I do not know how I would have gotten along without any money. Also, I would probably have been required to go to the US embassy the next day (Monday) to get a new passport, but how would I even have been able to get to the city? Those are, fortunately, things I did not have to deal with. Upon arriving at SFO, I thought that it would be best if I used the global entry lane where I would be able to speak more 'intimately' with a CBP agent. I went straight by the GE kiosks to the CBP agent at the GE booth and explained that I'd lost my new passport at HKG airport and had to use my old one to get back to the US. No reaction. I showed him the HKG airport police report for the lost wallet. He simply scanned my old passport, examined the data, looked at me, handed me back the passport, and asked me to go the door marked as "Secondary" at the end of the hallway. There was a long line when I got there. I went to the counter and explained that I needed to catch my connecting flight in less than hour, so I was in a bit of a hurry. I was simply told to take a number and have a seat. However, within a couple of minutes, someone came from the back office, picked up my documents and called out my name. He asked me to follow him to the back. He asked me what had happened and I told him that I had a brand new passport, which I left on the backseat of a taxi in HKG, so I used my old passport, the only form of ID I had with me, to come back to the US. He just smiled, handed me back my passport and simply said "I see that you have another plane to catch; welcome home." That was it. In retrospect, I believe that it was so easy for me to clear CBP because my old passport still had the CBP sticker that was affixed to it when I was selected back in 2009 to pilot the global entry program. What it meant is that I am truly a"trusted traveler", so CBP saw no reason to make a big fuss. GE, don't leave home without it! I am now home free, right? Think again. I needed to clear security check again at SFO, to go from international to domestic gates. With my BP and passport in hand, I took the PreCheck lane. When I got to the TSA agent, she took the BP, scanned it and I got the three beeps and a green light, but then she saw the two holes in my old passport cover (indicating that it had expired) and made a big fuss. She would not let me through unless I produced another piece of ID. I told her the story about how I lost my wallet, showed her the HKG police report, and said that I had no other form of ID. I tried to reason with her and asked her how I could have been standing with her well inside the terminal coming from HKG if I had not cleared CBP check?! Did it not mean anything to her that PreCheck also cleared me? She would not relent and said that the supervisor had to approve. Tick... tock...The supervisor finally showed up, cleared me within seconds, but the damage was done. When I got to the gate for my p.s. flight back to JFK, the door had been shut and the flight was about to take off. Fortunately, there was another p.s. to JFK less two hours later, and I was booked on it, including confirming an upgrade to BF, which had also cleared on the flight that I'd missed. Kool. I spent the time in a new UC that just opened, then at long last I took my final flight back home. At JFK, I took a yellow cab with no money on me. I told the driver about my ordeal, and promised that I had several jars full of coins at home that would have enough money for his fare. I would throw in a big extra tip for his time and understanding. When we got home, I decided to run to my favorite sushi bar/restaurant next door to borrow money from the owner, a friend, to pay the cab driver. Last week, I sent off the application for both a new passport book and passport card (as a back up), since I will need it to attend a conference in Seoul, SK, in September. After I get the passport back, I will request a replacement for my NEXUS card. Within 1 day I had replaced all my 11 credit cards and one debit card that I'd lost with the wallet. There was no cash in it, so that whoever picked it up must have been quite disappointed... I will never again keep all my IDs in one place... In sum, it is possible to get back to the US without a valid passport but a bit of luck may be necessary. For all the maligning of everything UA lately, I give my highest recommendation to the UA check-in crew at HKG for going above and beyond the call of duty to make sure that I was on that 744 flight back to US. Without their help, I do not think that I would have gotten off as relatively easy as I did. The next time I am at HKG, I will take a huge teddy bear to those folks as a token of my appreciation (any ideas for other ways to thank these agents would be appreciated). Cheers!