Book UK airport parking two to six weeks before you fly. Earlier than that and operators have not begun discounting to fill the car park. Later and prices climb as spaces go, sharply in the final week. The drive-up price is roughly double the pre-booked one at every airport.
Airport car parks price like airlines, not like shops. There is no fixed rate that gets discounted; there is a yield curve that responds to how full the car park is for your specific dates. Book when occupancy is low for those dates and you get a low price. Book when it is high and you do not.
That is why the advice to 'book as early as possible' is wrong in detail even though it is right in spirit. Very early bookings sit at a standard rate because the operator has no information yet about how that week will fill. The discounting starts once forward bookings give the operator a picture, which in practice is around six weeks out.
The final fortnight is where prices rise fastest, and the final week is where they rise most. At Gatwick in a summer peak we have seen the same eight-day booking move by more than £20 inside ten days.
Gatwick fills earliest of the airports in this set, because it runs a single runway at very high utilisation and its car park capacity is tight relative to its passenger numbers. Bristol and Leeds Bradford also fill early in school holidays because both have constrained sites with limited room to expand surface parking.
East Midlands rarely sells out at all, having been built around a large freight operation with generous land. Cardiff, Exeter and Inverness are similar. At those airports the booking window matters much less, and turning up without a booking — while still expensive — is at least possible.
The reason people leave it late is usually uncertainty about the trip rather than indifference to price. The answer is the flexible rate rather than the late booking: at most operators a flexible rate costs a few pounds more than the non-flexible one and refunds much closer to the date.
Compare that to what leaving the booking to the final week costs — routinely £15 to £25 more at a busy airport — and the flexible rate booked early is almost always the better financial decision, even if you end up cancelling.
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