Debentures and hospitality are the only remaining tickets for both Wales' home RBS 6 Nations matches at the Millennium Stadium.
Tickets for Wales against Ireland on February 4 2007 in the opening round of matches and Wales against England on March 17 in the competitions closing game have otherwise sold out.
WRU Group Chief Executive Roger Lewis said: It is a fantastic achievement to have sold out for both our home fixtures in the Six Nations. Those two games promise to be two truly mouth-watering games, as all countries prepare for the World Cup in the autumn.
We have hospitality packages on sale catering for every need but for those true Welsh fans who wish to purchase tickets for matches and events at the Millennium Stadium for many years to come, a debenture could be the perfect Christmas present for someone special.
With the number of debenture holders soon to reach the 20,000 mark, this will be the last chance to buy debentures - there will be no further issue in the near future.