It was revealed last week the 45-year-old is the number one choice of chief executive Xu Ke to become the Baggies next manager.
Ismael has a £2million release clause in his contract at current club Barnsley.
Albion spent the weekend locked in talks with their Championship rivals in a bid to negotiate that fee.
But the Express & Star understands they have now decided to stump up the full £2million in a bid to complete their move for Ismael within the next 48 hours.
Ismael is now in talks with the club to finalise his contract and backroom team.
And there is now an expectation from all parties that the ex-Bayern Munich defender will be Sam Allardyce's successor.
Proving everything goes to plan, Ismael will be appointed in time for the start of pre-season training.
He will also be able to play an active role in recruitment over the next few weeks as the Baggies attempt to secure a return to the Premier League at the first attempt.
Born in France, Ismail – who now has German citizenship – guided Barnsley to the Championship play-offs in his first season in charge at Oakwell.
That achievement put him on the radar of a host of clubs with the boss having also been considered for the vacancies at Sheffield United and Crystal Palace this summer.
Ismael made 13 appearances for Palace during his playing career and has previously been head coach of Greek outfit Apollon Smyrnis and Austrian side LASK.