How far ahead do you book a goshiwon for the March intake?

You are right that goshiwon do not take bookings months ahead, and that is exactly why the timing question is different from other housing.

How it actually works: goshiwon fill and empty monthly. Most operators will not hold a room more than one to two weeks out, because an empty room for three weeks costs them more than your booking is worth. Trying to lock something in from November for March is not usually possible and is where remote-payment scams find people.

The realistic timeline for a March intake:

- December to January: research. Identify three or four neighbourhoods, look at listing sites to learn the price bands, note buildings from Naver Map.
- Two to three weeks before arrival: start contacting. This is when operators will actually talk about specific rooms and dates.
- One week before: confirm one by phone or KakaoTalk with the room number and price in writing, paying on arrival.
- On arrival: view and pay.

The competition point people are making is real but it applies to a narrow window. Late February and late August are the two busiest weeks of the year because every language program in Seoul starts within days of each other. In those weeks the good rooms — window, private bathroom, near campus — go quickly, and what is left in the first week of March is the interior rooms nobody wanted.

So the practical advice: arrive ten to fourteen days before your term starts rather than two or three. You then view rooms in the calm week before the rush, and you have time to do your bank, phone and ARC paperwork as well.

If you want certainty before you fly, book a guesthouse for the first four nights. That is the thing you book in advance, not the goshiwon.