Contact William Hill customer service. You can call William Hill at (702) 827-4171 phone number, write an email, fill out a contact form on their website sports.williamhill.com, or write a letter to William Hill US Holdco Inc, 6325 S. Rainbow Blvd, Suite 100, Las Vegas, Nevada, 89118, United States. William Hill is operated by WHG (International) Limited, a company registered in Gibraltar. William Hill is licensed and regulated by the UK Gambling Commission ( Number: 000-039225 R-319373-009 ) for customers in Great Britain, and licensed by the Gibraltar Government and regulated by the Gibraltar Gambling Commissioner (RGL no. This website is operated by William Hill Global PLC, a company registered in Malta with registration number C96298 and registered office at William Hill Global PLC, Tagliaferro Business Centre, Level 7, High Street, Sliema SLM 1549, Malta.