Apex domains cannot have CNAME records.
Question and response
Question
dig xifos.co.uk. NS
Answer
xifos.co.uk. 4 NS ns3.xifos.net.
xifos.co.uk. 4 NS ns1.xifos.net.
xifos.co.uk. 4 NS ns2.xifos.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0