need tube/rail help please

There's a single Watford Junction station, which is served by both TFL's London Overground and the other rail companies. If you take the slow all-stations service, that will be London Overground. There's no Underground service to Watford Junction - the Metropolitan Line to Watford (no suffix) is a different station some distance away.

Northern Line to Euston will be the quickest route from Belsize Park.

The Travelcards for Zones 1-2 do cover rail as well, but Watford Junction is much further than Zone 2. You could buy a ticket at Euston (tell them that you have a Travelcard out to the edge of Zone 2 and the ticket may be cheaper), or if your seven-day Travelcard is on an Oyster card, you can put PAYG money on the card as well and use that.

(Be careful of your spellcheck/typing: Waterford is in Ireland)

There isn't an underground station at Watford Junction (any more) - it is National Rail or Overground.
It may be sending you to Watford rather than Watford Junction.
If I put in Watford Junction Rail Station as the destination it does say to go to Euston on the Northern Line, thence by London Midland (National Rail) to Watford Junction.

You don't say whether your travelcard is a paper ticket or on an Oyster card. If the latter add money to it for Pay as you Go. Otherwise buy a day return ticket from Zone 2 boundary to Watford Junction at Euston. You may find though that this is little different from the cost of a ticket starting from Euston.

Under 11s can travel free with an adult between Euston and Watford Junction. This is not the case with all routes in and around London so do check if you have any others planned.

OK thanks everyone!

We will probably have the paper travelcards, planning to order them online in advance.... We could do the oyster I guess, still trying to figure that out - we arrive Heathrow like 9:30pm... I know we will need an extra ticket for that anyway. Seems that to get the kid discount for my non-free 12 year old, we have to take the oyster card to a window, apply discount... seems like a hassle to me - maybe it's easier than I think to just get those when we get there (my thought is that no open window that late, so we would have to do the discount at another time). I am pretty sure we will be about same cost with oyster vs. 7 day (we are there for 5 full days, plus an arrival late night, and early departure last day, but needing to ride both of those days).

We do have a trip from Heathrow in, and then for one adult + free kid out to Watford Junction where we need supplement tix. Otherwise, we should be in zones 1-2. Taking Rail out on the last day.

On the main line railway, London Midland included, children over 5 are not free. 5 to 15 are half price.

According to this page of the TfL site it is also free on National Rail services between Euston and Watford Junction, amongst a number of other routes, when accompanying an adult. Surprised me too, although under 16 fares are overly complex in London, as is all this 'red' and 'green' stuff for differing rail routes (which fortunately the overwhelming majority of visitors need not get into).

That is what TfL would like to happen, but if you look at the London Midland website you will see no such concession. They take the National Rail approach.

There is at least one error on that TfL page, at least by implication. When it says that the child can travel free with a person using a Freedom Pass (Freedom Pass is a local London benefit for senior residents and disabled) between Euston and Watford Junction. On the line between Euston and WFJ the Freedom Pass on the National Rail companies of Southern Railway and London Midland is only valid between Harrow and Wealdstone and Euston. It is only valid at Bushey and WFJ on the Overground.

This pedantic rant is to say that different websites and different authorities have different takes on similar issues.

I can tell you that after many many years of dealing with tickets on one of the National Rail companies that we only apply one set of children's ages. 0-5, 5-15, over 15, and then the various discounts and Railcards.

Maybe right, maybe wrong, but that is how it is in the real world.

National Rail also has a list of routes where accompanied under 11s can travel free as a 'special offer'. This list does not include Euston to Watford Junction, but it does include a number of the other routes listed on the TfL site. It is dated April 2006 which shows the principle has been around for a few years now.

It is shameful that contradictory information is publicised to rail users though. I suspect there might be confusion somewhere with the Overground trains on this route (which are National Rail, even though TfL usually want to hide this).

Ok thanks, I am making my final plans.. and of course I have one more question! :)

If they buy the day return ticket when they leave Euston, do they have to pick a return time then? I am not sure how long they will want to spend there - I would hate for them to rush, or to be sitting around ready to leave.

So how does the timing work?

Thanks!!
Kim

And one more - let me see if I can tack it on here...

I think we want to buy a Family and Friends railcard, since we will use it to go London-York and York-Glasgow (and possibly a bit in Scotland... valid there too?)

I think we need a UK address to ship it - possibly we can get the lady at our rental flat to get it. Or can we buy it at the station when we get the Watford ticket? That is the same kind of train right? And my understanding is that I can go ahead and book discounted tickets without actually having the card, I just need to have it in hand before I travel on that ticket, correct?

Thanks sooooo much for all of your help!!! I do appreciate it so much!
Kim

Yes you can buy it at any staffed station ticket office, although I would try to avoid busy times.

You can buy tickets beforehand although as you realise they can only be used accompanied by a valid railcard.