It’s a one-for-one deal.  So you would use your first Gen 1 for 30% off a single Sonos product (Gen 2 in your case) and the second Gen 1 off a second Sonos product (also a Gen 2 in your case).

Thanks very much Danny for clarifying this for me.

I have checked the boxes to upgrade 2 speakers and received the return labels; the site is so confusing, how do I order the replacement speakers.

Getting answers from Sonus is impossible you can be on the phone for hours

Go to www.sonos.com and log in with your account, then go to the store and you’ll be able to order with your trade up discount.

Note that some bundles are eligible for the 30% off.  So you could use one discount on the two Play:5 bundle and save the other for something else.  Just add an item to your cart to see if the discount applies.  

Does anyone know if the 2x Sonos One speaker bundle is eligible for the 30% off?

Yes it is. It counts as a ‘single product’.

Excellent cheers :)

Even a 5.1 TV setup counts as a single trade-up.