Ethics of participation: consent, payment, vulnerable groups

If citizens take part in your workshops, interviews or surveys, you answer Yes to the question on human participants in the ethics issues table of the proposal, and you must then write an ethics self-assessment. According to the Commission guide How to complete your ethics self-assessment (version 2.0, 13 July 2021), that text becomes part of the grant agreement and can be checked later. Version 2.0 was still on the Funding and Tenders Portal in October 2026.

The process

The Horizon Europe Programme Guide (version 5.1, 15 September 2025) calls the process the Ethics Appraisal Procedure: an ethics review before the project starts, then checks, reviews and audits during it.

Ethics screening. Independent ethics experts screen all proposals above threshold that are considered for funding. Screening can oblige you to appoint an independent ethics advisor.
Ethics assessment. Proposals flagged as serious or complex get an in-depth assessment before grant signature. It ends in clearance, conditional clearance or no clearance, in which case the proposal is rejected.
Ethics requirements. Conditions due after the project starts enter the grant agreement as ethics deliverables.

The Annotated Grant Agreement (version 2.0, 1 April 2025) adds that all necessary ethics opinions and authorisations must be obtained before the task concerned starts, and kept on file.

Informed consent

The self-assessment guide expects participants to be told the aims, methods and implications of the activity, that taking part is voluntary, and that they can withdraw at any time without consequences. Consent is normally given in writing. Non-written consent, for example in cases of illiteracy, must be formally documented and independently witnessed. At proposal stage, project-specific templates of consent forms and information sheets are enough.

The guidance note Ethics in Social Science and Humanities (5 July 2021) was drafted by experts for DG Research and Innovation and states that it is not official EU guidance. Where written consent is culturally inappropriate or could expose participants to harm, it asks you to explain in the self-assessment how consent will be documented by other means, for example orally.

Vulnerable groups and children

For potentially vulnerable participants, the ethics issues checklist asks for the type of vulnerability, the recruitment and inclusion criteria, the consent procedure, and procedures that protect participants from coercion and undue inducement. The SSH note asks whether the same results could be obtained with a less vulnerable group, and counts people in a dependent relationship with the research team, such as students, as vulnerable.

For children, the checklist asks for the age range, assent procedures and parental consent, welfare measures and a justification. Assent is the child's own agreement, sought in addition to the consent of parents or legal representatives. Activities with children should take place only if studies with consenting adults would not be effective, risk and burden are minimal, and the results benefit the group. The age of consent differs by country.

Personal data

A list of participants or a mailing list already counts as processing personal data in the guide's examples. The guide asks you to collect only what the project needs, to anonymise or pseudonymise where possible, and to give participants the contact details of the data protection officer (GDPR Articles 13 and 14). You remain responsible for contractors that process data on your behalf, for example a recruitment agency holding the contact list.

Incentives and payment

Here the Commission documents say little. The self-assessment guide mentions undue inducement only as something vulnerable participants and persons unable to consent must be protected from, and the SSH note has no section on payment. Outside the programme, the UK NIHR payment guidance (version 1.9, December 2025) notes that vouchers are usually offered to under-16s instead of cash, and that payments can affect welfare benefits.

Guidance specific to participatory research

The ECSA Ten Principles of Citizen Science (September 2015) ask project leaders to consider copyright, intellectual property, data sharing agreements, confidentiality and attribution (principle 10), to give citizen scientists feedback (principle 5) and to acknowledge them in results and publications (principle 8).
The Horizon 2020 project PRO-Ethics published an Ethics Framework and Guidelines for Participatory Processes in the Activities of Research Funding Organizations (version 4, December 2024).