I received a letter with my maiden name (married 8 years). All details correct, including middle name initial, other than the use of 'Mrs' (I would have been a Miss!). Reference to a Pension Scheme Arrangement. I read everything on here and just gave them a call. They were trying to trace someone with this name and the same birth year as me. They asked me to confirm my date of birth but I said I didn't want to give any further personal details over the phone until I knew more. He was obviously used to this reaction so explained it would be in connection to a pension I'd paid into. he asked a couple of other non evasive questions - whether I'd lived at a certain address (which I hadn't lived at) and whether I'd worked for an insurance company (which I hadn't). At that point he said that I wasn't the person they were trying to trace, thanked me for calling and apologised for wasting my time. My hunch is they are genuine. But it's right to be cautious about giving over personal details.