London 2 for 1 ticket - can I use an underground travel card?

[littleredsquirrel]

We want to go to the Tower of London on Sunday, two adults and two children. We're driving to London but will go on the tube to the tower. Can I use a 2 for 1 ticket with a travel card or do I have to have an overground rail ticket?

If anyone knows that would be really helpful.

I've cut and paste from their website

What kinds of train tickets are valid for this promotion?
2FOR1 and special offers/admission vouchers are available with almost ANY type of train tickets issued to London (or to the Attraction Destination) on normal 'paper' ticket stock (i.e. not electronic or 'smartcard' but for exceptions see below) and valid on the day you wish to the visit the attraction, theatre, or restaurant, e.g. National Rail issued tickets include Off-Peak, Super Off-Peak, Travelcard, Advance, Anytime, Season Tickets, GroupSave and various promotional travel tickets that may be issued from time to time, etc...
By way of recognition most 'paper' rail travel tickets show the Double-Arrow (or 'crows-foot') National Rail logo, then you're safe to assume it is valid. If you are unsure in any way please check yours on our ticket types page or ask at your local staffed National Rail station.
London Underground issued tickets (including Travelcards issued by London Underground ticket offices and agents), Heathrow Express tickets and Eurostar-issued tickets are NOT valid and will not be accepted at any attraction.

Yep, furball definitely correct, you need an overground ticket. Where are you planning to park? You can go to your nearest train station and buy the cheapest train ticket. You need 1 per adult usually

Where are you parking? You can get round this from buying your travel cards from a railway station, not underground.

As help says you still buy a travel card but from a railway station not a tube station. For example, Ealing Broadway (has tube too but counts as train station).

I'm worried now there might be a requirement that it has to be bought from an outer station. So not zone 1 or 2.

The hotel is Chelsea harbour so right next to imperial wharf station. We might be ok then if we buy a travel card there?

Ok on the off chance this isn't too late, I'd stop on the way in and buy travelcards on the way in- you can specify for a later day.

Just to update for anyone else we bought our travel cards at Imperial wharf overland station and they were accepted on the 2for1 offer.