Transfer done but

I have done a transfer for the next saison, is the transfer sum already taken out my current transfer budget or will the transfer sum be taken out in the next saison of the new transfer budget? 

Thanks in advance

Depends how you're paying. If the fee is up front then it will be taken from your budget as soon as you press confirm transfer, doesn't matter when the player joins. If it's over time, say 12 monthly payments, the first payment will come out the following month, so if you confirm the transfer in February the first monthly payment will leave your budget in March