On 26 May, 14:22, "mark" wrote:
Visited the Grand Designs Exhibition in London earlier in the month.

Got a call today saying that following me completing a survey I'd won a
weeks holiday in Spain.

I had to confirm age bracket and that I owned a passport and my own home.

So what's the scam?

mark

They may insist that you buy their very expensive travel insurance,
and offer you very inconvenient flight dates and times from an airport
nowhere near where you live.