Outcall means the therapist crosses the city to you after dark, because the house keeps no studio, no parlour and no door of its own anywhere.
Plenty of people typing erotic massage into a phone at midnight still picture somewhere to walk to: a lit doorway, a bell, a receptionist behind a counter. This house has none of that. There is no studio, no waiting room and no address anyone could be seen entering. Every booking runs the other way, and the only door involved is one you already hold a key to.
You stay where you are: a hotel room above the canals, a rented flat in the Jordaan, an apartment in Oost with the curtains drawn. She crosses the city to you, carrying whatever the booking calls for in one ordinary bag. Forty-five therapists are on the roster and the office works through the whole clock, so a request at four in the morning is handled exactly like one at nine in the evening. The arrival window is forty to sixty minutes to anywhere central, one figure for every neighbourhood.
Because she comes to you, the practical details are yours to supply. A street and house number is not always enough in Amsterdam: add the floor, the name on the bell, and whether the building has a lift. In a hotel, say whether she should come straight up or whether you will meet her downstairs. Mention anything likely to slow the final minute, such as a courtyard gate, a door code, or a staircase steep enough to need both hands.
The room is yours to set as well. Dim the lamps, silence the phone, leave the shower free. Outcall hands you control of the setting, and a night tends to follow the way its room was prepared.
The city of Amsterdam, at any hour. Schiphol and the hotels around the airport are handled by arrangement rather than on the standard window. Nothing beyond the city is served. Wherever you are inside it, the figure comes off the same ladder, and the hotel room guide covers the quieter logistics of receiving someone late.