The WRU has identified a number of unofficial hospitality functions being held across Cardiff which more than 1,000 people are due to attend.
Leaflets will be handed out in Cardiff on matchday informing individuals who have purchased the packages that they risk being refused entry to the ground.
The Welsh Rugby Union is mounting a special operation to identify the unofficial events and identify the holders of null and void tickets.
The Union has also informed the Office of Fair Trading and the Advertising Standards Authority about the unofficial hospitality providers in a bid to protect fans.
On Friday a special team of investigators operating on behalf of the WRU will target the unofficial sites to alert purchasers to the problem. Holders of null and void tickets face being turned away from the Millennium Stadium before the game kicks off.
Organisers of the events have been contacted and told that the match tickets being offered are null and void and they could face legal action. Some unofficial operators have already ceased their planned operations as a result of threatened legal action from the WRU which will allow the investigators to focus their attention on the remaining venues whom seem insistent on going ahead.
The WRU has appointed Events International as its licensed and official offsite hospitality operator and supporters who buy packages from them will gain entry to the ground as they will be in possession of valid match tickets.
The WRU’s move to police the sale and distribution of its match tickets is to ensure money is kept within rugby for the benefit of the national sport of Wales.
The Millennium Stadium Manager, Gerry Toms, said: “We are determined to regulate the trade in hospitality packages for the benefit of all concerned.
“We are following in the footsteps of organisations like the RFU which have already taken similar steps to control this trade.
“Our member clubs can still sell tickets to Events International above face value as part of a legitimate commercial trade which will generate cash for their development.”
The WRU is now able to recognise tickets that have been the subject of unofficial hospitality packages
