marketing material opt in or opt out

as a consumer do I have to chose to opt out of receiving marketing material and communications or intentionally chose to receive it.

I notice that various websites/contracts are different some say tick box to receive it, some say tick box to be excluded. Whats the legal position, I looked at data commissioner website but no luck

Moved from Askaboutlaw
to Consumer Issues and Rights

I think they changed it a while back from opt out to opt in as in you tick the box to get the bumf rather than to reject it.

if electronic comms opt in, otherwise opt out.

See [broken link removed].