CEUS is a programme launched by the NCN in cooperation with the funding agencies from Austria (FWF - Austrian Science Fund - Fonds zur Förderung der wissenschaftlichen Forschung), Czech Republic (GAČR - Czech Science Foundation - Grantová agentura České Republiky) and Slovenia (ARRS- Slovenian Research Agency - Javna agencija za raziskovalno dejavnost Republike Slovenije) in line with the Lead Agency Procedure. The aim of the programme is to fund basic research projects in all areas carried out jointly by research teams from two or three countries involved in CEUS programme.

In February 2020, an international CEUS-UNISONO call was launched for research projects carried out in bilateral or trilateral cooperation by the Polish, Austrian, Czech and Slovenian research teams. Under the CEUS-UNISONO call, FWF, GAČR or ARRS will act as the lead agency and perform merit-based evaluation of the proposals. CEUS-UNISONO call announcement.

In September 2020, proposals for funding research projects carried out in bilateral or trilateral cooperation by the Polish, Austrian, Czech and Slovenian research teams will be accepted under the OPUS call, with the NCN acting as the Lead Agency. More information on the terms pursuant to which CEUS proposals can be submitted under the OPUS 20 call.