The 25-year-old central midfielder was persuaded to remain at the Baggies last summer but he is keen to explore a move to a bigger club and wants to remain in the Premier League
The combative former DR Congo international impressed for Roy Hodgson's former side last season as the Baggies achieved a top-10 finish in the Premier League, and Mulumbu remains confident of securing a move away from the Hawthorns.
"We have already started talking to teams like Newcastle and Tottenham," Mulumbu told Mercato 365.
"For now, I'm leaving it all in the hands of my agent and I hope to have good surprises on my return from vacation."
The 25-year-old has gone on to become a key figure in the West Brom side since making his loan move from Paris Saint-Germain permanent in 2009, and believes his form throughout the course of last season has placed him firmly in the shop window to perspective suitors.
"Last year, I thought it would be a little premature to go because it was my first full season," he added.
"But I confirmed my promise this season. I continued to show all my abilities and I think I now have to look for another challenge. That's why I hope to join a club in another class.
"I had a good year, I'm pretty confident and I will leave it now to my agent.
"I'm going to go on holiday and come back stronger because I know that another big season lies ahead."