The B1 and B2 forms in the ERC application

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May 5, 2026

B1 and B2 are the central scientific documents of the ERC application. They are submitted together, but they serve different purposes: B1 makes the case for the research idea and the Principal Investigator, while B2 makes the case for the project's implementation.

A useful shorthand is that B1 answers "WHAT is this proposal about?", while B2 answers "HOW will the project achieve its goals?"

This article explains how each part functions, how to approach it, and how the two parts work together in the evaluation process.

Background: the ERC application and evaluation

The ERC application consists of:

1. Part A – the online administrative forms, including the budget table, description of resources and time commitment.
2. Part B1 – the cover page, Part I of the Scientific Proposal (5 pages), and the Curriculum Vitae and Track Record (4 pages).
3. Part B2 – Part II of the Scientific Proposal (7 pages) and the Funding ID appendix.
4. Mandatory supporting documents, such as the host institution support letter and, where relevant, PhD certificate, eligibility-extension documents and other relevant annexes.

For Starting, Consolidator and Advanced Grants, the ERC evaluation process has two main steps. At Step 1, only Part I of the Scientific Proposal and the PI's CV and Track Record are evaluated. At Step 2, the complete proposal is evaluated, including Part I, Part II and the budget.

Synergy Grants follow a different evaluation structure, with three steps and some differences in the B1 and B2 format. Most notably, Part II of the Scientific Proposal is longer for Synergy Grants.

A note for applicants familiar with pre-2026 ERC calls

ERC proposal terminology and structure changed from the 2026 calls onward. What used to be commonly referred to as the Extended Synopsis is now framed as Part I of the Scientific Proposal, included in B1.

The former "full scientific proposal" logic has also changed. B2 now contains Part II of the Scientific Proposal, which focuses primarily on implementation.ERC guidance also clarifies that feasibility is no longer assessed at Step 1.

This change affects how the proposal should be written: Part I should not try to compress the full implementation plan, and Part II should not simply repeat the conceptual case already made in Part I.

This structure and evaluation logic shape how each document should be written.

We will start with B1, which is the basis for the first evaluation step.

A closer look at B1

B1 plays a decisive role in the first evaluation step. After reading B1, the panel members decide whether the proposal should proceed to the next evaluation step or be rejected.

As such, B1's main role is to convincingly portray the WHAT: what the project aims to investigate and why it is important, what gap it addresses, what makes it original, and what makes the PI well positioned to lead it.

And this will be done through the two central B1's components:

• Part I of the Scientific Proposal
• Curriculum Vitae and Track Record

The PI profile: CV and Track Record

Unlike many collaborative funding schemes and national grant programmes, the ERC is an investigator-driven grant. This means that the Principal Investigator's profile is an important part of the evaluation.

The reviewers are not only asking whether the project is excellent. They are also asking whether the PI has the intellectual capacity, creativity, independence and relevant track record to lead an ambitious frontier-research project.

For this reason, the CV and Track Record should not be treated as a generic academic CV. It should be carefully curated to support the ERC case. The applicant should highlight achievements, outputs and contributions that demonstrate their ability to advance knowledge in their field and successfully carry out the proposed project. For more on this topic, see our dedicated article on who is "ERC material". 

Part I of the Scientific Proposal: the core research idea

Part I of the Scientific Proposal is the scientific heart of B1. In only five pages, it must present a creative, rigorous and ambitious research idea in a way that is both scientifically convincing to experts and accessible to a broader evaluation panel.

A strong part I should usually include:

1. the current state of knowledge;
2. the key motivation, knowledge gap or scientific challenge;
3. the project objectives;
4. the overall research strategy;
5. the project's originality and ambition;
6. the expected contribution to the field.

The key ERC qualities should be woven into the narrative. These include novelty, high-risk, high-gain, non-incremental thinking, investigator-driven research and, where relevant, a clear hypothesis-driven structure . These qualities should not appear as slogans. They should emerge naturally from the scientific logic of the proposal.

Is a general project description enough for B1 / Part I?

No. A general or high-level description is not enough.

Part I must present a rigorous, well-reasoned and original research idea. Although Step 1 panel members may not be specialists in the applicant's exact niche, they are experts in the broader research field. They can evaluate whether the idea is important, original and scientifically convincing.

It is also possible that at least one panel member will have expertise close to the applicant's specific field. Moreover, if the proposal reaches Step 2, Part I will also be read by external reviewers, who are expected to have more specific expertise in the relevant research area.

For this reason, B1 should be accessible but not vague. It must show scientific depth, intellectual ambition and a clear research logic.

How much methodological details are expected in B1 /part I?

B1 should not include a detailed work plan, extensive methodology, full risk tables, detailed team descriptions or budget justification. These elements belong mainly in B2 and Part A.

However, B1 cannot rely on vague promises. Part I must establish strategic credibility. It should outline the overall approach clearly enough for reviewers to understand how the applicant intends to address the research question.

There is no universal rule for how much methodological detail is needed in B1. The right level depends on the project, the discipline and where the novelty lies.

For example, a project whose main novelty is conceptual may need less methodological detail in B1. A project whose novelty depends on a new experimental setting, model, technique or methodological framework may need to explain more of that approach already in Part I.

A closer look at B2

The B2 contains Part II of the Scientific Proposal and the Funding ID appendix.

As it becomes available to panel members and external reviewers at Step 2 of the evaluation, it complements part I and allows the reviewers to assess whether the project is feasible. Namely, whether the project's methodology and work plan are credible, appropriate and sufficiently developed.

In this sense, B2's main role is to describe the HOW: how the research will be carried out, how the methodology supports the objectives, how risks will be managed, and how the project will be implemented in practice.

Hence, part II must aim to include:

1. a detailed explanation of the methodology;
2. a clear work plan;
3. the relationship between objectives, methods and expected outcomes;
4. scientific or technical risks;
5. mitigation strategies and alternative routes;
6. the role of team members or collaborators, where relevant;
7. a realistic project timeline;
8. relevant resources, equipment or infrastructure, where needed to explain the implementation.

As in Part I, the key ERC qualities should still be present. B2 should continue to reflect novelty, high-risk, high-gain, non-incremental thinking, investigator-driven research and hypothesis-driven strategy . However, in B2 these qualities should be connected to implementation.

Should part II/B2 only describe the tasks and methods?

No. B2 should focus on methodology and implementation, but it should not read like a technical annex.

Methodology in an ERC proposal is not the same as the "Methods" section of a scientific article. It should not be a list of techniques, tasks or procedures without a reasoning thread.

The concept remains important in B2. A strong B2 connects the objectives, research logic, methodological choices, risks and expected outcomes. It shows not only what the PI will do, but why this is the right way to do it, and how the PI thinks.

Where do preliminary results go – part I/B1 or part II/B2?

Preliminary results can appear in both B1 and B2, depending on their purpose.

Preliminary data that support the hypothesis, theory, concept or originality of the research idea may be appropriate in B1.

Preliminary data that support the feasibility of the approach, the suitability of the experimental setting, or the reliability of a method may be more appropriate in B2.

This is case-dependent. The key question is what role the preliminary results play in the argument.

Should part II/B2 describe the resources or a detailed timeline?

B2 may refer to resources, equipment, infrastructure or experimental settings where they are needed to explain the work plan. However, the main budget table and description of resources belong in Part A.

A timeline is valuable and expected in Part II, but it should be appropriate for ERC. The proposal does not need to look like a highly rigid project-management document with strict deliverables and milestones at every stage.

ERC projects are ambitious and often risky. The timeline should therefore show structure and credibility, while leaving room for scientific exploration.

Should applicants cross-reference between B1 and B2?

Cross-referencing should be used carefully.

In general, applicants should avoid cross-referencing from B1 to B2. At Step 1, reviewers do not have access to B2. A sentence such as "see Part II for details" can therefore create a gap in the Step 1 reading experience.

Cross-referencing from B2 back to B1 may be more acceptable, because at Step 2 reviewers have access to the complete proposal. Even then, it should be limited, careful and tasteful. Reviewers should not be required to jump constantly between documents. Each part should have a clear internal flow.

How should the Funding ID table be handled?

Applicants should provide the information requested in the template. Although this appendix does not have a page limit, it should not be used to add hidden scientific content that belongs in Part I or Part II.

Additional practical tips

When writing both parts of the ERC proposal, keep the following principles in mind:

• Ensure your text is clear and focused. Our Top EU grant writing tips can help;
• Keep the visual aspects in mind; use figures, tables or diagrams where they improve clarity;
• Remember the audience, and avoid the Top 6 ways to annoy a grant reviewer;
• Avoid logical jumps in the text;
• Make sure the narrative in B1, methodology in B2 and resources in Part A are fully aligned.

Conclusion

B1 and B2 are complementary parts of one ERC application. B1 reflects the WHAT, B2 describes the HOW.

In practice, however, the line between the WHAT and the HOW is not always obvious. Strong ERC proposals require careful thinking, strategic choices and a clear understanding of what belongs in each part. This is especially true for ambitious, high-risk projects, where the concept and methodology are often closely intertwined.

If you are preparing an ERC application and want to make sure that B1 and B2 work together as a clear, compelling and competitive proposal, we are here to help, do not hesitate to contact us.