Charlotte G

I've recently taken on a new freelancer role for a CIC and they are asking me to provide my UTR number as a part of a weekly timesheet prior to invoicing to work on a monthly basis. When undertaking work on a similar for other CIC's I have not been required to do so and have to date been under the impression that as this is personal information I am not required to do so. I would like to know what if any basis it is appropriate to disclose my UTR in documentation relating to my invoicing some one?