The balance on arrival is whatever part of the fee is still owed when she walks in, settled at the start in cash of any major currency, by card or in crypto.
Every fee here is paid in one piece or in two. The balance is the piece that travels with her.
Usually half. A first booking of ninety minutes costs EUR 270: EUR 135 cleared in advance, and EUR 135 is the balance. An overnight is EUR 1,250 split down the middle, EUR 625 on each side of the door.
Occasionally all of it. Just one kind of booking arrives with nothing paid in front: a same-day hour or two with one therapist, for a client the house has looked after before. Then the whole EUR 180 or EUR 360 is the balance. That is the exception. Everything else sends half first.
Now and then, less. Credit from an accepted force majeure claim on an earlier booking comes straight off the figure.
Cash, in euros or in any major currency, converted at the day's rate. Dollars, pounds or francs can come straight out of the wallet you flew in with. Card works. Crypto works. The balance need not match the method of the deposit; a Wise deposit and a cash balance get along fine.
At the start, before anything else happens. Settle it in the first minute and the rest of the booking has no money in it. Counting notes at the end of two hours is nobody's idea of an evening.
It is not a late deposit. A booking that needed half in advance does not turn into a pay-at-the-door booking because the client would prefer that. The two halves have two fixed moments, and neither one moves.
The figures are on the prices page, currencies and cards come up in the FAQ, and the half that goes first is defined under deposit.