The bookmaking and gaming group hired the design agency following a seven-way pitch to enhance its online customer experience via improved navigation and site design.
The agency will work across several projects and businesses within the Victor Chandler Portfolio, with the first work going live in the new year.
The bookmaker's online portfolio includes sports betting site www.victorchandler.co.uk and online casino The Spin Room (www.thespinroom.com).
Earlier this year, The Spin Room featured in the launch of a dedicated betting and gambling channel on ISP Tiscali's portal. The channel brings together Tiscali's gambling and betting partners, which include fixed-odds specialist SportingOdds, for easier navigation.
NowWashYourHands is already a preferred supplier to bookmaker Ladbrokes.
It recently worked on a CD-Rom to support Manchester United's betting site, accessible through www.manutd.com and powered by Ladbrokes. The CD-Rom is currently being distributed at the club's home matches and some local Ladbrokes outlets.
The agency has also carried out work for Camelot, parent of the National Lottery, the most recent activity being a microsite for its Cars & Cash scratchcard.
"We are growing our knowledge of the betting arena now," explained Glen Conybeare, business development director at NowWashYourHands. "If you try to place a bet on a site and you're not used to it, it can be a scary experience. We now have that betting experience and by understanding it, we can help design something friendly."
Joe Coughlin, project manager at Victor Chandler, said: "We have a history in telephone betting, but online is becoming increasingly important for us and we want to make sure our online presence is consistent across all our products."