Announced, met or expected: the arrival settled before anyone sets out

The minute people remember

Most of what can go wrong with an evening goes wrong in its first minute, and very little of it is anybody's fault. A companion crosses a lobby and cannot tell whether she is expected at the desk or at the lifts. A porter asks a polite question that nobody thought to answer in advance. A host stands at the window of a mews house while she stands, just as politely, at a door she was told would be open. None of these moments is dramatic, and every one of them is avoidable. This house avoids them by settling the arrival before anybody leaves home.

There are three ways in. She can be announced by name at a hotel desk, she can be met by you in the hall of a building that keeps a porter, or she can walk straight in through a door you have left on the latch. They are not interchangeable. Each belongs to a particular kind of building, each asks one small thing of you, and each begins a slightly different evening. What follows is how I weigh the choice when a message reaches the switchboard, and what I ask of you in return.

Announced at the desk, as the grand hotels expect

The oldest of the three is the one the great hotels were built around. Tell reception, as you come in or by telephone from the room, that a guest will be asking for you. She arrives, asks for you by surname and room number, and the receptionist rings up. Within a minute she is on her way to the lifts with the building's blessing, which in a large hotel after ten at night is well worth having.

It suits the houses with a big lobby and a desk that is staffed through the night, and it suits them precisely because nothing about it is hidden. A woman who asks for a guest by name is the most ordinary visitor a hotel receives. Near Dover Street that means the old house one street east on Albemarle Street, and the corner house across Piccadilly from the bottom of the street. Both are the kind of house where a caller with a name ready is simply looked after and then forgotten.

The desk asks one thing of you, which is that the room stands in your name or that you have told reception whose name it stands in. It is also the right choice wherever the lifts answer only to a room key after a certain hour, as they now do in a good many London hotels. A companion who has been announced is shown to the lift, and you are spared the walk down to collect her.

Met in the hall: porters, mansion blocks and serviced flats

The second way belongs to the buildings that keep a porter rather than a reception: the red brick mansion blocks of Mayfair and Marylebone, the serviced apartments above the shops, the flats a firm keeps for colleagues who are in town for the week. A porter is not a receptionist. He knows the residents by sight, he is not there to announce anybody, and a stranger who asks him to ring up to a flat is asking him to do something a little outside his job.

So you come down. You give me the minute you will be standing in the hall, she arrives on it, and the porter sees exactly what he sees twenty times an evening, a resident greeting a guest and taking her upstairs. Two minutes of your time buys an arrival that nobody in the building will think about again. It also means that the first thing she sees is you, and that your first words are exchanged in a hallway rather than across a threshold, which suits most people rather better than they expect.

The hall is the right answer at a hotel too, whenever you would rather begin downstairs. Meet her in the lobby, walk through to the bar for a drink, and take the lift together later. The arrival then looks like exactly what it is, two people meeting for the evening, and reception plays no part in it at all. If a table is involved, the same thinking runs through the hour before the table, which makes the case for beginning a dinner at a bar.

On the latch: mews houses and private front doors

The third way is the quietest, and it needs the most care in the arranging. A mews house, a private house on one of the squares, a flat with its own street door and no staff anywhere near it: in each of these there is no desk to announce her and no hall to meet her in, only a door. The kindest thing is to leave it on the latch for the minute she is due, so that she can step in off the cobbles instead of standing on a doorstep waiting to be seen.

I arrange it in a fixed order. The minute is agreed in writing. She sends one line as she turns into the mews, which is your signal to lift the latch if you have not already done so. She knocks once as she steps in, so that nobody is startled, and you drop the latch behind her. The door is never left open on a guess, and never for a moment longer than it needs to be.

This arrival suits a host who dislikes lobbies of any kind, and it is the usual one in the back streets of Belgravia and behind the Mayfair squares. Patricia, who lives in SW1X and seldom leaves it after dark, prefers it to either of the others, on the grounds that it lets an evening begin as though it had always been going on.

Written down before anybody moves

Whichever way you choose, it goes into the confirmation. When you write to the switchboard I ask for the hotel, the surname on the booking and the number of the room, or, for a private address, the street, the floor and the name on the bell. Then I ask the question most people have not yet considered: announced, met or on the latch? The answer sits in the same thread as your companion's name, the length and the figure, and she reads the very same line before she sets out.

That is the whole reason it works. Nothing is left to be settled in a doorway by two people who have not yet met, in front of a third who is paid to notice things. If the building has a peculiarity, a side door locked after nine, a porter who goes off duty at midnight, a lift that stops one floor short, tell me and it goes into the thread as well.

Everything after the door follows the usual course of an evening at your address. The hour is £250, and every longer length is set out on the tariff. The fee is handed to your companion in person once she is inside, at the figure already written down, and neither of you needs to mention it again.

Dover Street, where all three sit within a few doors

No street in London shows the three side by side better than Dover Street. It is short, Green Park station is a minute from its lower end, and within its length and the few streets around it you will find hotel lobbies with a desk, galleries with flats above them and a porter below, and private doors that give nothing whatever away. A guest who stays nearby for a week can easily meet all three arrivals before he leaves.

Molly lives six minutes' walk away and knows the entrances of the street as well as most of the people who work behind them. For a desk arrival across a large marble floor I often suggest one of the slender women of the circle, and Samanta above all, who crosses a lobby as though she had been sent for, which is exactly the impression a desk arrival wants to give. If you would rather choose by some other quality, every face is in the Salon.