Its both, can either have phone delivered and send your trade in to them or do in store, the difference is they are offering a £100 extra on trade in valuations currently
If you do in store you get a voucher which you use against the purchase, if you have delivered i think its bacs transfer
https://www.currys.co.uk/services/ways-to-pay/trade-in.html#HowToTradeIn
If you do in store you get a voucher which you use against the purchase, if you have delivered i think its bacs transfer
https://www.currys.co.uk/services/ways-to-pay/trade-in.html#HowToTradeIn