We have the background as to why you require this information please?
The only 1st Plus financial group I know is a secured loan company owned by Barclays.
However, in their marketing, they used the word Plus rather than the plus sign +.
If you have never sold carbon credits to them, it is likely to be a scam.
If they are asking you for money, it is likely to be a scam.
Do you have a physical address for them?
Thank you. If there is no physical address, that would really concern me.
I think they are unlikely to be the same organisation as the loan company.
Companies house lists various 1st plus companies but there are deserved. Not fit the description of yours. There is no listed with 1st +.
There are lots of First Plus companies of various descriptions and but six of those have also been dissolved. It may be a trading name of another company.