Yes, they've started already. I had a lengthy conversation with a 'supervisor' on the line that claims to be from Microsoft saying they know my computer was "Being used by scammers" (!) - I said they can't get in to use it and pretended not to understand what he was saying about technology. That was 20 minutes of his life he won't get back! If its anything to do with loft insulation, boiler renewal, double glazing, replacement soffits (what the hell are soffits anyway?) I tell them to contact my landlord. (You can do that even if you own your house - they aren't interested if they can't deal with you directly!) Another trick to try is let the phone ring 5 times before answering it - scammers dial multiple numbers then disconnect once one answers. Not failsafe, but often saves your bother. On mobiles, check the number calling - if it doesnt begin with "0" or "+44" its from outside of the UK. You can check where from on this page
https://en.wikipedia.org/wiki/List_of_mobile_telephone_prefixes_by_country