I guess you've tried not leaving a space between the two halves of your postcode.
Failing that it seems your only other choice is to email them and ask, the only phone number on the website seems to be for press enquiries.
Alternatively the advice from AlexNL above seems better than mine!
I can understand your feelings. It's a bit odd that MTR (or their payment provider) require you to provide these details yet don't require them to be valid, and even give you some tips on which information to provide.
If you're going to travel with SJ, it can be interesting to sign up for SJ Prio. This is SJ's free loyalty programme (something like Flying Blue at Air France/KLM), and they give you a welcome bonus: a 15% discount on your first trip. Furthermore, they have some partnerships and promotions running from time to time which may be of interest for when you're in Sweden.
Carrying ID: do you have a reason for not doing so? It can make your live easier when something happens.
I'm... not sure. Didn't you get something to download or maybe e-mailed to you?Thanks for the tips.
I have booked the day return trip on the website using the fake ID details as suggested above.
There doesn't seem to be any tickets or anything. How do we collect these to travel?
I assume there is a bar on-board these trains.. are the prices reasonable?
Thanks
Did have major issues with the bar tho. Brought our own journey GnT premixed cans though, from England. Then they announce you must not drink your own alcohol, this is not permitted! But they don't take cash!!! No cards we have and even if we did, I'm not paying the foreign transaction fee for a few drinks.
This company is seriously taking the pee ! Can't drink your own, and can't buy on board... what the f*** do they expect people to Do???
They assume you will have a credit card. Even 10 years ago Sweden used cards far more than we do. And it's not significantly more expensive than buying currency anyway.
It's illegal to consume alcohol on Swedish public transport other than drinks bought and consumed in the bar car.
Wow. Good job I didn't get caught thenon another note, the MTR trains are very plesent

I am now having second thoughts of travelling with such a shoddy company that tells customers to enter fake ID details into their own website!!
Might just use the SJ train. Bit more expensive but probably less complications..
Also neither of us will be carrying ID in the trip... except probably bank debit card and maybe E111 health cards.
Sorry to have a rant, but I really couldn't live in this nanny state country.
We arrived at the airport getting off the train, and was told to join the queue for the 120sek airport train tax (what is THAT about- imagine having to pay a tenner fee for using the Picc to Heathrow even if you have a travelcard that covers the zones!). We couldn't pay in cash. So I had to leave my passport as "security" and go to the newsagent to pay this in case.
Sorry to have a rant, but I really couldn't live in this nanny state country.
We arrived at the airport getting off the train, and was told to join the queue for the 120sek airport train tax (what is THAT about- imagine having to pay a tenner fee for using the Picc to Heathrow even if you have a travelcard that covers the zones!). We couldn't pay in cash. So I had to leave my passport as "security" and go to the newsagent to pay this in case. Other tourists in the same boat here.
Check in was fine, fast track security fine, everyone friendly. At the duty free we were going to buy some booze, maybe a couple of bottles of gin, as we had about 600seks left. They don't allow you to buy any alcohol whatsoever if travelling in the EU. I have never come across this!
Secondly, in the business class lounge, they wouldn't even let my Mrs have a Baileys because it was before 11am!! We feel insulted...
Sorry to have a rant ...
>snip
Wow. Good job I didn't get caught thenon another note, the MTR trains are very plesent
Sorry to have a rant, but I really couldn't live in this nanny state country.
We arrived at the airport getting off the train, and was told to join the queue for the 120sek airport train tax (what is THAT about- imagine having to pay a tenner fee for using the Picc to Heathrow even if you have a travelcard that covers the zones!). We couldn't pay in cash. So I had to leave my passport as "security" and go to the newsagent to pay this in case. Other tourists in the same boat here.
Check in was fine, fast track security fine, everyone friendly. At the duty free we were going to buy some booze, maybe a couple of bottles of gin, as we had about 600seks left. They don't allow you to buy any alcohol whatsoever if travelling in the EU. I have never come across this!
Secondly, in the business class lounge, they wouldn't even let my Mrs have a Baileys because it was before 11am!! We feel insulted...
You have posted on here about visiting Sweden previously. If you don't like the way they do things there - card purchases the norm for everything, restrictions on sale of alcohol etc - why go back ? There must other countries which are more to your taste.

Is it any different than the trams in Edinburgh, where a trip costs £1.60, unless you want to travel to airport, when it suddenly costs £5.50? But yes, 120 kr is a lot, and they should accept cash at the gate. Tip from a local: Take the train to Märsta and the bus from Märsta to Arlanda. Takes about 15 min longer, but saves you the station fee at Arlanda. Or take the SJ regional train to Märsta, and then the bus.
We do have very strict alcohol laws in Sweden, as in most Nordic countries. Bars and restaurants are not allowed to sell alcohol before 11.00. And due to the Systembolaget monopoly, the stores at Arlanda are only allowed to sell alcohol to passengers travelling outside the EU. But if they could, they would have to charge you the swedish alcohol tax, and the bottles of gin would have been cheaper in the UK.
Given that you said you had a bank debit card earlier, couldn't you have used that? I know there's a charge each time you use it but I did some sums once and concluded that taking into account the much worse exchange rate when you buy notes it was either cheaper to use plastic everywhere or worth any extra for the sake of convenience.
!!!You have posted on here about visiting Sweden previously. If you don't like the way they do things there - card purchases the norm for everything, restrictions on sale of alcohol etc - why go back ? There must other countries which are more to your taste.
I am surprised the EU regulations on competition etc allow the strict alcohol laws. They should put Sweden under pressure to change this. It's unfair to the consumer.

Might want to try Germany - still very much a cash culture and alcohol *very* freely available and consumed.
Strange you mention Edinburgh, we are going there next month to visit. I didn't think about the Märsta tip. Out of interest, if we got off the train at the station before the airport and just got a cab from there to the airport, surely that wouldn't be anywhere near 240sek would it ? Maybe 80-90 sek ?