Eurostar is capacity limiting departures from Amsterdam, because they can’t cope with the passenger numbers, so the chance of getting passholder reservations is slim, unfortunately. They’re sending trains half-filled.

You can get the IC to Brussels and try from there.

Actually, looks like plenty of availability from Rotterdam on both days. So that would be better than Brussels.

Shame they’re sending trains half-filled… I’d like to fill one of those seats! Just checked Rotterdam to London and there only seems to be one later on Wednesday 12th or Sunday 16th… I’m looking on b-europe.com, maybe I’m missing something, is there a better website? Thanks so much for your reply!

Oops. Just re-checked and I was indeed looking at the wrong route.

Yes, from Rotterdam I see only the 12th or 16th at 1928. (Assuming you have a second class pass. If you have first class, there’s availability in Standard Premier on the 13th and 14th.)

If either of those dates are half-acceptable to you, you could book them and there’s a chance you might be able to change nearer the time for a €15 fee. But not at all guaranteed. And you would have to stick to Rotterdam.

If it has to be 13th/ 14th then Brussels is your only option.

Perfect, thanks so much! 

It’s not the train operator that is limiting the numbers, they would fill every train and probably have added more trains by now if they could. It is the inability of the immigration/customs agencies to deal with the numbers travelling that is the problem, just another brexit bonus to deal with.

There is a limited number of pass holder seats on the Eurostar between London and mainland Europe. On popular departures and during high season those sell out weeks, and sometimes months in advance.

The best place to see the availability of passholder seats and make reservations on the Eurostar is 

https://www.b-europe.com/EN/Booking/Pass#TravelWish

If you don't get any result, press "later trains" and eventually you will find the next available connection. 

If you have a mobile pass you need to generate a Pass Cover Number in order to make the reservation at b-europe. You do that here in the PCN generator:

https://community.eurail.com/news-and-announcements-39/pass-cover-number-generator-is-live-5653

I am sure t isn’t actually causing Eurostar much of a problem as the trains are simply an extension of trains stopping at Brussels and Lille so it can be filled with passengers to/from those stations, hence the reason tickets are available from Brussels. Remember most paying passengers will also simply use Thalys to.from Brussels/Amsterdam (another sister company).

Being an old cynic but I see it like sleeper train operators claiming lots of new services where all they are doing is getting publicity by shuffling their existing stock/capacity and joining them up on the way, much as Trenitalia has been doing for years with the night sleeper from Rome to Sicily - it splits/joins at Messina for Palermo or Siracusa. 

Add a couple of standard non-sleeper carriages (with a different running number) and it suddenly seems capacity and choices are doubled.

The Dutch Eurostar extension causes a bit of issues in both directions. Only a part of the train can be filled in the Netherlands to London, as Brussels and Lille also have quite some travellers wanting to go to London. From London, they often reserve big parts of the trains for people travelling to the Netherlands, limiting availability to Lille and Brussels.

Any other train does not have this, but the strict secutainment protocols lead to this.

Anyway, usually always good alternatives in the Netherlands, by taking the (hourly!) reservation free IC to Brussels (or the more expensive Thalys). In Brussels there are more Eurostar choices, with a bit of longer travel day of course. And also less time needed for the procedures, in comparison to the NL, since there’s more space in Brussels.

Only if the last Eurostar of the day from London travellers for Northern France or Belgium is the one to Amsterdam, that’s a bit annoying. But also not insurmountable and easily avoided by buying a ticket/seat reservation to Rotterdam or Amsterdam. No biggie for experienced railers, but leading to a lot of confusion with occasional traveller, leading them to less ideal alternatives. But letting other people know this other options, is what where here for on this forum anyway.

I’m curious what it’s going to give when Thalys and Eurostar are fully merged, also operationally. Just sad that we have to give up the elegant Thalys name branding up for that merger :)

Is this not the case though for all long distance trains - passengers board and leave all along the journey leading to a balancing act by the operator. Obviously before reservations it was first come first seated (much like most commuter trains at rush hour,) Now with reservations the operators have to choose between first booked first given for any and all combinations or rationing for each boarding point. 

Obviously we poor passengers do not know which model is in use for any train, just the ease or difficulty in getting reservations from our choice of start and end stations. 

With Eurostar it is less obvious on the Amsterdam route whether they do it by allocation for each station from London or just first come first served.

I don’t know whether they allow boarding in Lille or Brussels to Amsterdam or simply leave vacated seats empty to the terminus in Amsterdam - leaving the way open for Thalys trains.

Lille to Brussels can be done with Eurostar, Brussels-Amsterdam was possible for a short while, but they have cut it down not so long ago. Lille-Amsterdam I don’t know, but I think that also not possible as it doesn’t give any results on the planner.

I think I underestimated what a response my query would get - there’s such a wealth of information needed to work through the network of rail systems! I’m so grateful for all your wise words and suggestions! 

You all will probably roll your eyes, but I appear to have made a rookie error... I first paid for the evening Eurostar from Brussels then couldn’t find any reservation free tickets from Amsterdam (couldn’t find the reservation free IC as BrendanDB suggested) and so ended up paying for a reservation on a much earlier Thalys train instead (the wording was different - it’s a “supplement”, not a seat reservation, but even so...) As a result I have landed myself with a 4 hour wait in Brussels when I was hoping to maximise my time in Amsterdam! 

To clarify, I’m going in the following order:

Amsterdam - Brussels - London 

Does anyone know if there is there any way back from this?!

Ah, that’s a shame.

The Intercity is about an hour slower than the Thalys. You could switch to that, and abandon the reservation on the Thalys, if the timings work, but remember you want to be in Brussels a good hour before your Eurostar.

At least you know know more than you bargained for about Eurostar’s operational problems!

-

Edit (again): Just found the conditions which state that you can exchange your Thalys reservation for free, subject to availability. Which is obviously better than the IC idea.

Specifically for Amsterdam, there's also the problem of limited terminal capacity. That will remain the case until the new terminal is ready, which should be in 2025:

https://www.treinreiziger.nl/thalys-en-eurostar-willen-verdubbelen-maar-kopen-geen-nieuwe-treinen/

To answer my own question on intermediate journeys on Eurostar they accept bookings on their website from Lille to Brussels at £26 (UK) but no other combinations on that route unless you are going to/from St Pancras.

I think you should be able to do this on the Thalys website. Put your booking reference/ PNR (should be at the top of your PDF reservation) into the Tickets section of the website.

@AmyVik And unfortunately interrail seat reservations are not refundable, but they are exchangeable. So try regularly if you can rebook to a later Thalys, but as it are easter Holidays then, demand might be higher than usual.

The IC leaves at hh:28 in Amsterdam on weekdays, with a travel time of 2:49 to Brussel-Zuid.

And if you would find yourself too early in Brussels, Parvis de St. Gilles/St. Gillis Voorplein is on walking distance from Zuid/Midi station,has quite some café/bars to enjoy yourself a bit before going through the Eurostar check in.

And if you’re looking for a bit of Culture, the Wiels (modern art museum in an old brewery) can be a nice idea too, also not too far from Brussel-Zuid/Midi