I ordered a deal recently (magazine subscription), but wasn't able to order online because not all of my vouchers had an online code. Vouchers without the code can't be redeemed online.
I downloaded the order form (available on the clubcard deals homepage) and sent it off to the UK address on the form.
I was in tesco athlone today where lovely lady on customer service put me though to clubcard deals on their phone and she said click "How to order a deal" and a page called "clubcard deals order form" appears. This didnt this morning but did there a minute ago.
Anyway very handy/quick way to order deals. Well done tesco...