When "roaming" with a North American cell phone in Spain, do I dial only the 9 numbers of the local business's phone number?
Or must I preface it with +34/ 0034?
I have researched this online and I see contradictory responses. I could proceed by trial-and-error but prefer to ask the experts.
Second question:
Do they still have pay-phones in Spain and, if so, do I dial just the 9 numbers to reach a local business/ resident?
Thanks for answering my questions.

You just dial the number. If that doesn't work try adding +34, but you shouldn't need it.
If they have pay phones again you just dial the 9 (or 7 or 8 for mobiles) number.

If we are programming a number into our phones we always use +countrycode number, but if we are just dialling a number we have found whilst there we don't use the country code.

That's very helpful - thanks very much.

I've always just called the number without the extra country pre-fix.