Great Western Coffee Shop

Next week I am due to visit London for one day at work and then an evening meeting. It will only be my fourth trip to town since March 2020. However, does anyone have any experience of using a contactless card from Twyford? Specifically - will my plan below work? I believe this is my best option as it’s a one-off trip, and I’m not the right age anymore for a railcard! I believe I just have to tap the yellow readers at the various stations?

Journey 1: Twyford to Paddington, then tube to Zone 1 station for work. (£17.50 in Peak according to the single fare TfL guide. My concern is am I charged for the GWR but then the tube separate?)

Journey 2: zone 1 work - zone 1 for evening meeting. (£2.40)

Journey 3: zone 1 tube to Paddington, then home to Twyford (assume £10.90 offpeak but be interested to understand if the tube is separate?)

This seems better value than a 1 day travelcard? What ‘dwell time’ will it allow at Paddington eg for a bite to eat? Will I be able to use the GWR express services?

All looks good, and contactless does seem your best option and it's valid equally on TfL Rail and GWR, though GWR don't seem over-keen to promote it.  There's a page on their website (search for "contactless") which links to the detail on the TfL website but I've failed to find it though the website menu.

As you are presumably starting in the morning peak the only relevant Travelcard is the Anytime one which is overpriced for your purposes but if you did later happen to make enough extra journeys you'd be capped on contactless and not charged any more than the paper ticket price.  The charge won't be split at Paddington (that's why you were able to look up a fare for the whole journey) unless you clearly split it into separate journeys by doing something such as ...er... stopping for a meal en route. The times are rather buried on the TfL website as most people don't need to worry about them, but for interest they are 20 minutes into the Underground but 40 minutes the other way which allows for a wait on the concourse before going through the gates to the TfL Rail or GWR train.  Breaking your journey part-way without paying extra is one of the benefits of paper tickets that you do lose with pay as you go, but against that there is the flexibility of not having to know in advance if you will make enough journeys for a Travelcard to be worthwhile, or even where you are going!

Thanks that’s really helpful, and really good to know the dwell times! I think the only minor problem to the plan would be if the line from Paddington were completely blocked coming home, as I’d then need a ticket from Waterloo, but it seems a risk worth taking!

That raises a very interesting point - and maybe in a separate thread............... If the line is blocked for a long period, tickets are generally accepted via an alternative route. If somebody is touching in and out, using contactless, how would this work if the lines between Reading and Paddington are blocked? GWR 'normal' tickets are generally accepted from Waterloo to Reading.

It's worth pointing out that the Single Fare finder (https://tfl.gov.uk/fares/find-fares/tube-and-rail-fares/single-fare-finder) page can sometimes be misleading.

Yesterday I used contactless between Wimbledon & Slough and return. I was expecting to pay £5.30+£5.30 = £10.60 but was charged £15.90 instead.

I suspect that the "Fares" box which comes up first displays the price avoiding Zone 1 and you'll need a tube map to work out how to do that.
However, the obvious routes are via zone 1. District line to Paddington or SWR to Waterloo then Bakerloo to Paddington. Those routes work out as £8 each way and are shown underneath as "Alternative Fares" but you may not even see that section without scrolling. And why would you scroll when you have already seen that the fare is £5.30.

TfL should probably include a "via" or "Not via" note on that page to avoid confusion.

Look down the page for "Alternative fares". For that journey I get three more routes via Zone 1, all at the same prices of £12.40/£8.00.

Add: Sorry - didn't read your post carefully! You're right, what's missing is the warning "only valid if you avoid Zone 1" in the first box.

I went to London (and back) via Paddington two weeks ago, and was struck by the removal of almost all the semifast evening services that used to be allowed on an off-peak ticket. That's because the last time I went that way on a weekday was not only pre-Covid but before December 2019. All we were left with was Crossrail, plus the semifasts at 17:56/18:26/18:50/18:56 (all stop at Twyford).

The December 2019 edition of the T10 timetable had clear red markings to tell you which trains were not OK with an off-peak ticket. The current T10 has nothing of the kind, so the only way to know which trains are allowed is to use a journey planner and go through the list - rather tedious. I don't think there is still a leaflet listing them - or is there?

Given we were trying to avoid crowded trains, we gave up and spent the hour sitting in a 345, which had plenty of seats free. I did cope with the toiletlessness, but found the seats felt very hard after an hour. My sister felt the same, but was more irritated by the incessant stream of nagging announcements.

For the record, we used travelcards, but then we were going to zone 4 (for a family funeral). PAYG would be less but only by 30p, unless you go by the scenic route (via Ealing Broadway/Shepherds Bush/Willesden Jn/Highbury&Islington), so not really worth it. For anyone really keen to avoid crowded trains, I can recommend the GN service from Moorgate during the day!