We are sure that as a referring agency you will already be only to familiar with the requirements of GDPR, so please do not be offended if the following is stating the very obvious.
When you refer a client to us please ensure that you are very clear with them as to what information you will be supplying to us and obtain their permission to do so.
As stated in our privacy statement for recipients we have legitimate reasons for requiring:-
Name; address; telephone number; family makeup
For obvious reasons we also ask for any parcel relevant information such as:-
dietary requirements; allergies; approx. ages of very young children (for nappies)
see also “Parcel Recipient Personal Information“