Transfer Rules - Schengen

Schengen zone and vaccine requirements are not the same. Schengen zone rules apply to immigration and customs between Schengen zone countries. When you land in Amsterdam you will go through immigration -- passport control - since this is your first entry into the Schengen zone. When you hit Portugal you will go through customs because this is the first time you had access to your checked luggage. BUT -- it is no big deal as you simply walk through the green door -- Nothing to Declare. You are correct on your other example since UK is not part of the Schengen zone and you should stay in-transit side of immigration and security. You would go through both immigration and customs when you exit in UK.

Requirements for the virus is a different ball game with changing goal posts. You should met the requirements of your destination.

Thanks for clarifying.
Right now, I meet the Covid requirements for Portugal but not Amsterdam. I didn't want to end up buying tickets I wouldn't be able to use.

You would go through both immigration and customs when you exit in UK.

There is no exit immigration or customs when you leave the UK.

You will go through both when you enter the UK.

These days you need a bit more definition when talking about being in Transit, layovers, etc.; in relation to Covid.

For both instances, even though you go through immigration in Amsterdam on your way to Portugal, you will be in transit if you are arriving, staying in the secure zone, and leaving within hours.

For both instances, there are requirements for the Netherlands you need to meet. It is not the full entry requirements, and varies due to monthly changes, but the times I was through it was filling out a health declaration, making a quarantine declaration (which basically stated I was exempt since I was in transit), and that was it.

The best source for information on this is the Schiphol Airport site: https://www.schiphol.nl/en/ You can see there is a tab for "Smooth Transfers"

For a bit more information, for US>AMS>UK, when you land, you are let out into the International terminal. You may very well just be able to go to your next gate with never encountering any officials, except gate agents.

For the US>AMS> Portugal option, you will look for an exit from the International terminal indicating Transfers or Connecting Flights, not the exit for ground transportation and baggage claim. You will then go through an immigration point specific to transfer passengers, and then move into the Domestic terminals, without leaving the secure zone...then on to your gate for Portugal

I'm specifically looking at tickets for USA-->Amsterdam-->Portugal. Where I get nervous, is that Amsterdam considers fully vaccinated as including a booster, but Portugal only requires a negative Covid test.

I have been vaccinated 2X and most likely will have gotten and recovered from Covid by then (lots of exposure). I know that the easiest route would be to get a booster shot, however, I had a negative reaction to the vaccine. Very much better now, but not completely back to normal.

Travellers from United States (see 183 additional countries) are allowed to transit through the Netherlands as long they meet any of these conditions:
1. Fully vaccinated travellers;
2. Travellers going to an EU or Schengen country must show permission to enter that country and stay in the transit zone of the airport.
3. Travellers going to a non-EU and non-Schengen country must have a confirmed outward flight ticket, they must stay in the transit zone of the airport and transit in a maximum of 48 hours on their way to a non-EU country.

I'm thinking that I would be #2 which would require permission to enter Portugal.

You are travelling to an EU country/Schengen area country via the Netherlands. You must be able to show you have permission to enter the EU country/Schengen country in question. You can do this with a note verbale from that country’s embassy, for example, or another type of document that proves you can travel there. If you do not have such a document, the Dutch border authorities will determine whether you may travel via the Netherlands. Without a document showing you have permission to enter the EU country/Schengen country in question, you are advised to fly there directly and not via the Netherlands. If you will be making a short stop at a Dutch airport you may need an airport transit visa. This depends partly on your nationality. The Visa Advisor tool helps you determine whether you need an airport transit visa. Please note: the United Kingdom (UK) is not part of the EU/Schengen area.

...You would go through both immigration and customs when you exit in UK..... Sorry I didn't make that clearer. I was referencing exiting the airplane in UK and not exiting the UK.

I'm thinking that I would be #2 which would require permission to enter Portugal

Keep in mind that these rules are intended to apply to all passengers, including those that require specific visas to enter a country.

In your case, carrying a US Passport, that is your "permission" in that US Passport holders are entitled to visa free travel to a Schengen country for 90 days out of 180 without (for now) further permission. Of course, entry to any country is at the discretion of the border agents.

In regards to what constitutes "vaccinated"; some countries are setting limits on validity after the last shot or booster, but the Schengen countries are trying to align their requirements, so probably, what goes for Portugal, will eventually go for the Netherlands. The UK of course is completely separate.

However, I would not be concerned about getting stopped in the Netherlands due to vaccination issues while in transit, the airline will not let you board unless you meet requirements. So look at meeting Portugal's requirements, plus any transit requirements for paperwork to get through Amsterdam, and you will be fine. For better or worse, once the airline clears you for travel, no one will look at vaccination status.

This is for entry only though, once in Portugal, or the UK, separate requirements may be in force for entering a restaurant, a museum, or other venues.

Thanks, this helps. Regarding Portugal, they do not officially recognize the CDC card. So for that country, it's a matter of testing. If I want to eat inside, take a test at the door, etc.

We were there in August and as long as one is okay with testing, it's an easy country to visit.