Tax on used car

I bought a used car was given an old v5

just managed to contact the guy today

and was told he'd just received a new v5c but wasn't there when I purchased the vehicle

he's changed over ownership online to myself

and has sent confirmation of this

he's also sent a reference code to tax my vehicle but DVLA won't recognise is

what do I do

am I able to drive the car as it's still taxed?