http://www.irs.gov/instructions/iw2g/ar02.html automatically withholds IRS Specific Instructions for Form 5754 IRS Form W-2G IRS IRS IRS Instructions for forms W2-G and 5754 http://www.irs.gov/instructions/iw2g/ar02.html gambling winnings IRS IRS http://www.irs.gov/instructions/iw2g/ar02.html Instructions for Forms W-2G and 5754 (2016) can withhold 25 per cent gambling winnings http://www.irs.gov/instructions/iw2g/ar02.html 25 to 28 percent WG-2 as per IRS guidelines