No price has been published. The UNFCCC says only that pavilion and delegation office space is available on a commercial basis and is managed by the Turkish government, which handles the terms directly with each host.
This is the question we are asked most and the one with the least public information behind it. There is no rate card, no published per-square-metre figure and no fee schedule from either the UNFCCC or the COP31 presidency. Anyone quoting you a standard COP pavilion price is quoting something other than an official source.
The expression of interest window for COP31 space ran through cop31.center and has closed. Applicants were told outcomes from 13 July 2026. Whether a waiting list or a late allocation route exists is not stated anywhere public.
What is knowable is the shape of the commitment rather than the number: a pavilion is leased for the full two weeks, the host designs and builds it, staffs it, programmes every session in it, and arranges its own accreditation for the people it wants in the room. The build and the staffing usually cost more than the floor.