This is national grid. It is the same number that called me in the past when my bill was overdue. That wasn't a scam; my bill really was overdue. But I still didn't pay it by phone, I simply paid it electronically the way I pay all my bills, once I had the money to do so.
Currently, they are calling to schedule replacing my meter free of charge. This is because Mass state law requires the replacement every 7 years, even if the meter is fully functional. I converted from oil to gas seven years ago. Scam? No, not in my case.
But I'm glad so many others are suspicious in general. That is a healthy skepticism. For me, it checks out in this case.
They are ridiculously annoying--I finally made a week-end appt for the gas meter and they called me at the end of the day to say that there was a problem in Boston and they weren't going to come that day. I said please do me a favor and leave me alone for a month or two--which they did and then it started again, finally, they came and changed it but I can still hear the chick recorded on the message, it haunts me, "This is Natl Grid calling to make an appointment to change your gas meter...there will be no charge to you..." and I just got it again, distorted...they're back...
Caller # from Brooklyn, NY - wanted to set up an appt. to replace the gas meter. Told caller to contact the landlord. The caller (male) kept telling me that they needed to set up appt, and I repeatedly told him to call the landlord. I hung up on him. The dude was rude.