This is better than last year’s Black Friday promotion, because the start date of the (mobile) pass (which you can choose at any time after purchase) can be up to 11 months from date of purchase (as with non-sale passes); if you buy on the last day of the sale, the last date you can start using the pass is 17th November 2025 – so it can be used during the summer high season. Last year, there was a fixed last start date of 1st June 2024.

Interesting to see a disparity in the cancellation/refund terms between the UK National Rail site and the Eurail/Interrail site.

On myinterrail.co.uk it states you can cancel a promotional pass before start of use and get a refund less 15% cancellation fee. (In the FAQ section it says that promotional passes are non-refundable, but this section does not appear to have been updated for some time and not since mobile passes were introduced).

On interrail.eu it states that you can get a full refund on these promotional passes if you cancel within 7 days, or a refund less 10% cancellation fee (maximum €25) thereafter. Alternatively, pay for Plus (only €7 more) and get a full refund (except the Plus fee, unless within 7 days) if you cancel at any time.