Connecting Flights To and From Copenhagen - Connection Time and Process

It will take three flights to get there from Louisville.

I know flights are reduced during the pandemic, but who came up with that itinerary?

How much time do I need if I connect through Amsterdam, London, or
Paris, and switch airlines, e.g. from United to British Airways in
London?

Short answer: It depends. United to British Airways in London sounds like self connecting. And would involve changing terminals, so 4 hours or more I'd say.

And when you land in a European city for a connecting flight, do you
have to go through immigration control at the connecting country, or
just the final destination country (Copenhagen, Denmark)?

You go through immigration when you enter or leave the Schengen area.

And does it involve retrieving your bag, and re-checking it, and
clearing security again, like entering the U.S.?

If you are self connecting, yes.

Am I better off flying from the U.S. to Toronto, and taking a direct
flight into Copenhagen?

That sounds like a much better option in my opinion!

Note our host's Travel Tips in the blue menu top left. I forget if he warns that third-party booking sites are not always the best way to buy complicated itineraries that could have problems before (Covid) and after departure. Do you have Travel insurance, and does it exclude Covid as a Forseen Event?

You also need to evaluate whether you have a single ticket with all three flights (which you could get by buying the ticket on the United or Delta website), or if it is three tickets that absolve all three carriers from making sure you make your connections. Some cheaper ticket options are penny-wise and pound-foolish. (Don't take that personally, I'm saying so in a blunt way, because you asked for basic air advice. I certainly have made the same mistakes in the past.)

SAS normally has direct flights to CPH from Dulles, Chicago, and Newark . SAS is part of Star Alliance, but for some reason their flights never show up when you search on the United website. I see United Express flies between Louisville and all of those cities. Try searching on the SAS website. Alternatively, you might try calling United to see if they can book you on a flight with SAS as the transatlantic carrier.

SAS is part of Star Alliance, but for some reason their flights never
show up when you search on the United website.

SAS and United do not codeshare across the Atlantic, so it is easy to miss these flights and instead end up on some strange itinerary.

Try searching on the SAS website. Alternatively, you might try calling
United to see if they can book you on a flight with SAS as the
transatlantic carrier.

Due to lack of codeshare I don't think United will be able to book you on the SAS transatlantic flights. So I think your best bet is www.flysas.com

Thank you very much for the advice on SAS connections. I am not traveling until 2022, so I have time to work this out with my typical two flights to Europe, rather than three.

If this is not until next year, keep an eye out for SAS offers. They usually have sales now and then.

Fly SAS with one connection (O'Hare or Dulles) to CPH. We've been happy with our SAS flights and one connection is beter than two.

If earning United Miles is important to you: https://www.united.com/ual/en/us/fly/mileageplus/earn-miles/airline-partners/scandinavian-airlines-sas.html

MileagePlus members can earn award miles and Premier qualifying
credits on eligible SAS flights. To receive mileage credit, present
your MileagePlus number when you make reservations and make sure that
it appears on your boarding pass at check-in.

I found a great Louisville to Newark United flight, and a perfect connection with SAS in Newark, direct to Copenhagen, just like you said. But the SAS flights are not included in the United online system. So I called United with all of the flights info, and asked if they could book the connecting flight. After the person struggled, putting me on hold to talk to her supervisor, she said they could not book the SAS flights -- only the flights that appear in their system -- back to three flights to Copenhagen. So is there an easier way to book both flights (United and SAS) together, so my bags transfer automatically like any other connecting flight? Or do I have to land in Newark, retrieve my bags, and check-in at SAS as a separate flight -- and do all of this on the return flights? It is still likely faster than three flights from Louisville to Copenhagen, but what a hassle!

So is there an easier way to book both flights (United and SAS)
together, so my bags transfer automatically like any other connecting
flight?

Yes, www.flysas.com

Thank you Badger. Very easy on flysas, and they had the perfect connections I wanted. Talking to United was a waste of time. SAS is on top of things.