Heathrow to York by train

Piccadilly line Underground from Heathrow to Kings Cross St. Pancras (takes about 1hr), then Virgin East Coast from Kings Cross to York.

To get from York to Windsor will require multiple changes and using different services. The best bet seems to be to get the train from York to Kings Cross, then the Tube to either Paddington or Victoria, then either South West Trains (from Victoria) or GWR (from Paddington) to Windsor. Bearing in mind the number of journeys you'll have to make, a railcard may be a good bet.

Thank you for your reply. Is the rail card good on all lines?

My preference would also be to take the London Underground (Tube) directly from Heathrow to King's Cross station (allow one hour), from where trains depart to York. If you start with the Heathrow Express, it ends at Paddington station, then you'd still have to connect by Tube or taxi to King's Cross station. See www.nationalrail.co.uk.

A BritRail England Pass covering three train travel days within a month costs $237 for an adult, or cheaper for groups, seniors age 60+, and people under age 26. This would allow a flexible departure plan, instead of booking an Advance-discount ticket for a particular time on your flight arrival day and instead of running into the full-fare ticket of 105 pounds one way if you buy in the station. That's helpful given the possibility of delays between the flight, immigration, navigating the airport, etc. The pass covers all trains including the Heathrow Express but not the London Underground.

That rail pass link will also get you to info about the Two Together Card, Family Card, or Senior Card, if you qualify for one, which are not passes but allow discounts on train tickets.

Usually, just for one return long distance trip as you are planning, a rail pass isn't good value, as individual tickets in advance are likely to work out cheaper.

It is easier if you just cover Windsor as a day trip from London, as York to Windsor is a long journey via London.

I think you would find it cheapest to go on www.nationalrail.co.uk and put in for YRK > KGX and find the trains and fares for your desired date. (11 weeks out should give you the best prices but pay on the day for non pre-booked travel can be expensive). This will be cheaper than booking a through journey from York to Windsor. You should be able to find a train that will get you from York to London Kings Cross for £13 if you book far enough ahead. Click ‘details’ on the national rail website and it will tell, you who operated that train service - pre-book with them.

You should then be able to go to the ticket office at King's Cross and purchase a ticket to Windsor - which should include the underground. (If you put in for a journey from King's Cross to Windsor on the national rail website, it will tell you how to do it. Note that Windsor has 2 stations so you would need to know which one you are going to as the routes are different. They are about a 7 minute walk apart in Windsor.