Re-checking baggage for international to domestic transit at San Francisco? (long layover)

Question

I am looking at flying from Singapore to Chicago via San Francisco on United. My itinerary is: SIN > SFO (8h+ layover) > ORD

I understand that I am supposed to re-check my baggage at a bag drop counter right after I clear immigration at SFO. However, I am wondering if I will be allowed to drop off my bag so many hours before my connecting flight.

Also, if I instead fly into SFO on JAL and transfer to United, will I be able to drop off my bags early? I am hoping to explore the city during my layover as it will be my first time visiting the US in many years.

Answer 1

How early you can check your bags for the connecting flight will depend on whether they already have baggage tags on them for that flight or not.

If both flights are on a single ticket, then the carrier for the Singapore -> San Francisco flight should "tag" the bags all the way through to Chicago. When you arrive in San Francisco you will need to collect your bags, but then as soon as you exit the immigration/customs area you can turn left and you will come to the United international connection bag drop area where you will be able to re-check them.

The only exception to this may be if your flight is overnight. Some airlines will not tag your bags for an overnight connection, whilst others will. This is up to the initial airline, and sometimes they will do it anyway if you ask, so if your connection is overnight then you should ask at check-in for the first flight to see if they will tag them all the way through or not.

If you are on 2 separate tickets, especially if those 2 tickets are not on partner airlines (which JAL and United are not) then it's unlikely that your bags will be tagged for your connecting flight. After collecting them at San Francisco you will need to take them to the United Airlines domestic check-in counter (not the bag drop area mentioned above) to check in for your connecting flight - however officially they will NOT accept your bags until 4 hours before your flight. It is possible for them to accept bags earlier, but you'll be at the will of the check-in agents as to whether they will allow it or not.

Answer 2

I understand that I am supposed to re-check my baggage at a bag drop counter right after I clear immigration at SFO.

Correct

However, I am wondering if I will be allowed to drop off my bag so many hours before my connecting flight.

Yes. If this is a single ticket, the airline will take responsibility for your luggage, the same way as they would if you didn't have to clear immigrations and customs.

Also, if I instead fly into SFO on JAL and transfer to United, will I be able to drop off my bags early?

Yes. JAL isn't a Star Alliance partner, so this might include a "self transfer" if it's not on a single ticket. Even though, SFO is a major United hub and there are check-in counters and bag drop counters open at any reasonable time of the day and they will accept your luggage if you are within the check in window for your flight.

There is a difference between is single ticket connection and a two ticket connection (self-transfer). On a single ticket you can drop the bag right after you have cleared customs at the "recheck" area. For a self-transfer you need to lug it to an United check in counter.