HS1 Upgrade Ticket Validity

[Jonomac]

TLDR: what does the HS1 upgrade ticket from Stratford actually upgrade?

Starting from Canary Wharf I typically take the Elizabeth line to Abbey Wood and change to the Gravesend bound (Southeastern or Thameslink) train.

When there has been cancellations on either the Elizabeth line or Southeastern lines and advice to use alternative routes I've taken the tube or dlr from Canary Wharf to Stratford in order to take the HS1 back to Gravesend.

Each time I've bought an HS1 Upgrade Ticket at SFA in association with my existing ticket however sometimes (not always) the ticket gate staff have denied entry saying its not valid without me holding an original ticket from Stratford to Gravesend to upgrade.

My question is, what ticket should I be expected to be holding as the journeys I've checked online to get from Stratford mainline to Gravesend always include either transiting thru Stratford International or taking TFL services back down to Abbey Wood.

In the end some gate staff have let me thru, but then I'm left wondering what will happen in a conversation with the guard on the train.

 

[Watershed]

What original ticket do you hold in these cases?

 

[Jonomac]

What original ticket do you hold in these cases?

Either a Gravesend to Abbey Wood or Gravesend to Canary Wharf return.
If just to Abbey Wood then I tap in and out on the Oyster readers when joining the Elizabeth line.

 

[Watershed]

Ok, so the issue is that a Gravesend to Abbey Wood ticket can't be upgraded to allow travel on HS1. Buying a Gravesend to Stratford HS1 upgrade doesn't make an Abbey Wood ticket valid to Stratford International - they are two completely different journeys/routes. If it were possible to upgrade an Abbey Wood ticket, it would be a much cheaper way of getting to Stratford International than actually buying the intended ticket.

There aren't any point-to-point fares to intermediate stations on the Elizabeth line 'core' (i.e. Woolwich to Bond Street) so you would presumably have a ticket to Underground Zones 2-4 if you are searching to Canary Wharf.

A ticket from Gravesend to Underground Z2-4 can be upgraded to HS1 (there are versions both for HS1 and not for HS1), so that's what I'd suggest buying if you want to have the flexibility to travel via either route. It covers the Elizabeth line, as well as the Underground and DLR, for a single/return journey to a destination in Zones 2-4.

 

[Jonomac]

OK brilliant, I can see the logic with that. Thank you very much for the thorough answer!