The figures are cited by Sky Sports, via El Mundo Deportivo, who say that the total figure is around £20m (€21.9m) which is based on €17m plus further bonus-related agreements.
Bale is now leaving the Spanish capital on Thursday to travel to London and complete his medical and sufficient paperwork at Spurs to seal the deal, which will be a season-long loan arrangement.
It follows on from the player’s agent Jonathan Barnett confirming that Bale was in talks with Spurs over a summer return.
Despite previously claiming his client intended to complete the final two years of his contract in Madrid, Barnett has now opened the door to an exit.
Bale celebrated his 31st birthday last month and it has been widely reported that Madrid are prioritising the exit of the Welsh international this summer.
The report states that Bale is now keen on an exit from the Spanish capital to enjoy more playing time and prominence elsewhere, with Spurs – whom he left for Madrid in 2013 – the destination.