CCC'26 featured a program of several talks, including the inaugural Test-of-Time invited talk, spread over four days. For details, see the program and the list of accepted papers.

The conference had no tutorials, while the associated workshop, Complexity as a Kaleidoscope 2026, offered free registration and travel allowances for attendees.

Conference fees included lunch for all four days. Lunches offered standard Portuguese fare, with meat, fish, and vegetarian options.

The registration fees were:

Registration Fees (EUR / USD)
	Early (until July 10)	Late (July 11 or later)
Student	€190 ≈ $225	€220 ≈ $260
Non-student	€300 ≈ $350	€340 ≈ $400

CCC'26 was held from August 3–6, 2026, in Lisbon, Portugal, at the Faculty of Sciences of the University of Lisbon. The conference took place in the C3 building. The main lecture hall was room 3.2.15, with rooms 3.1.09 and 3.1.10 reserved for informal discussions and blackboard sessions. Lunch was served in the C6 building, on the ground floor in the canteen next to the patio outside. View the conference map.

Participants were advised to book accommodation early, as Lisbon is busy during the summer. Staying near the green or yellow metro lines gave direct access to Campo Grande, a ten-minute walk from the C6 building; Cidade Universitária on the yellow line was even closer.

Participants who needed a visa to enter Portugal could contact the local arrangements chair for a supporting letter.

Information about future activities in complexity remains available through the CCC announcements Google group.

The conference collected registration information to facilitate event planning and communication. Names, email addresses, status, and affiliation were shared with the Executive Committee of the Computational Complexity Foundation (CCF) for CCF Board-election eligibility and attendance statistics. Individual records are retained for no more than four years; statistical data are retained indefinitely. For privacy questions, please contact the CCF Executive Committee.

The open exchange of ideas and the freedom of thought and expression were central to the aims and goals of CCC'26. The organizers worked to provide an environment free of discrimination and harassment, and participants were expected to honour that commitment.

CCC 2026 was a participant in the SafeTOC initiative.

• Bruno Loff (Chair), University of Lisbon
• Diogo Poças, University of Lisbon
  
• João Ribeiro, University of Lisbon

For archival questions, please email the local arrangements team.