The company has approached a number of shops, but it has not yet put together a definitive list. However, agencies expected to be involved are Bartle Bogle Hegarty, WCRS and the incumbent, Poulters.
The bookmaker is looking to overhaul its entire brand as well as create a new logo. The winning agency will be asked to create a heavyweight TV and online campaign to break in September.
William Hill originally gave the brief to a design agency - Bulletproof Design - last year, but then put the project on ice until the outcome of the legislation changes were agreed.
Chris Edgington, the group director of marketing at William Hill, said: "With the Gambling Act coming in on 1 September, it is right and proper for William Hill to be considering its options."
Last month, the Committee of Advertising Practice and the Broadcast Committee of Advertising Practice finalised changes to the rules governing ads by allowing betting shops, casinos and online gaming sites to advertise on TV.
However, ads must not encourage socially irresponsible behaviour, appeal to children, be linked to seduction or suggest gambling can be a solution to financial concerns.