'prescribed information'

Tenancy Deposits

I place my tenant's deposits in the TDS. Although they send information to the tenant, i have been told that i still have to provide 'prescribed information' to the tenant. i am aso told that i must get them to sign to acknowledge that they have received, seen and agree with the prescribed information. what if they cant be bothered to sign? presumably i am at risk of being accused of not having provided it. I cant make them sign before they get the keys (as i would with the tenancy agreement) as not all of the information required for the 'prescribed information' is available at the time they move in. I would be most gratefull for any suggestions