Balance on arrival, the second half
The balance is whatever remains of the fee once a deposit has been paid, normally the other half, and it is settled at the door when she arrives.
On every booking that carries a deposit, the fee is split in two. The first half goes before she sets out; the second is the balance, and it changes hands at the door.
What it looks like in practice
Two hours booked the week before: one half of the two hour fee ahead, the matching half on arrival. Three hours on the day: half ahead because of the length, half on arrival. The overnight: half of the block price each way.
Currency
Every fee the house quotes is in euro. A balance in cash in another major currency is welcome, at an exact figure in that currency confirmed in the thread before she leaves, so nothing is worked out on the doorstep.
A practical note for regulars
Guests used to paying at the door in full sometimes forget, on a larger booking, that half has already gone. The thread states the balance before she sets out. Have that figure ready rather than the whole fee.
When it is settled
At the door, before the session starts, in the same way as a full door payment. Settling it first leaves nothing to discuss once the session is under way and nothing to remember when she leaves.
Ways to pay it
Cash in euro is the simplest way to cover the balance. Card and crypto are accepted at the door as well, and a guest who plans to use one of them can mention it in the thread so that she arrives ready for it. Whichever way he pays, the figure is the one already written in the confirmed booking, with nothing added on the night.