Lump Sum in Horizon Europe: What Changes and How to Adapt Your Proposal Strategy
The complete practical guide: what lump sum is, how it changes your proposal, and what it means if you are funded
Of all the changes in the current Horizon Europe work programme, lump sum funding is the one that most directly changes how proposals need to be written — and how projects are managed if funded. Yet it remains one of the most misunderstood aspects of the programme, particularly among organisations with strong Horizon 2020 experience who assume the new template works the same way.
Many experienced applicants build their budget the same way they always have, and only discover the mismatch during Grant Agreement negotiation — when the Commission asks them to justify their WP costs in a way the old model never required.
This post gives you the complete picture: what lump sum actually is, how it differs from the previous model, what changes in the way you write your proposal, the financial implications during implementation, and the six most common mistakes consortia make in the transition.
What Lump Sum Funding Actually Is
Under the traditional cost-based model, the Commission reimbursed a percentage of the actual eligible costs a consortium incurred. Audit processes checked every cost line against timesheets, invoices, and payroll records. The administrative burden was enormous on both sides.
Under the lump sum model, this entire logic is replaced. Instead of reimbursing actual costs, the Commission pays a fixed, pre-agreed amount per work package — regardless of what that work actually cost to deliver. If a WP is fully completed and its deliverables are accepted, the consortium receives the full WP lump sum. If a WP is not completed, payment is reduced or withheld.
Key point
The fundamental shift: from 'how much did this work cost?' to 'was this work delivered?'. This sounds simple — but it has profound implications for how you design work packages, define deliverables, structure your budget, and manage financial risk throughout the project.
Why the Commission moved to lump sum
The shift was driven by a long-standing criticism of the cost-based model: the compliance overhead it imposed on both beneficiaries and the Commission. Timesheets, cost declarations, audit certificates, financial corrections — the cost-based model generated enormous administrative work, much of it for costs that auditors would eventually approve anyway.
Lump sum removes most of this. No timesheets, no itemised cost reports, no receipt audits. The consortium agrees a fixed budget per WP at the start, delivers the WP, and gets paid. The simplification is real — but it comes with different risks and requirements that applicants need to understand before they start writing.
The Complete Comparison: Cost-Based vs Lump Sum
While both funding models support collaborative research and innovation projects, they differ significantly in how budgets are prepared, managed, reported, and audited.
Understanding these differences is essential for both proposal writers and project managers, as the funding model influences everything from budget preparation to project implementation.
Budget Structure
Cost-based model: Budgets are prepared per partner and broken down into cost categories such as personnel, travel, equipment, subcontracting, and indirect costs.
Lump sum model: Budgets are organised per work package, with each work package assigned a fixed lump sum that is agreed before the Grant Agreement is signed.
Payment Mechanism
Cost-based model: Payments are based on the actual eligible costs incurred during each reporting period.
Lump sum model: Payments are linked to the successful completion of each work package rather than the actual costs incurred.
Financial Reporting
Cost-based model: Partners submit detailed financial statements supported by invoices, timesheets, and other financial records.
Lump sum model: No detailed financial reporting is required. Instead, the consortium demonstrates that the agreed work package has been completed.
Audits
Cost-based model: Audits focus on whether reported costs are eligible, properly documented, and correctly allocated.
Lump sum model: Audits focus primarily on whether the agreed work has been delivered in accordance with the Grant Agreement.
Budget Flexibility
Cost-based model: Budget reallocations between cost categories are generally possible within the limits of the Grant Agreement.
Lump sum model: Flexibility exists within each work package, but transferring budget between work packages normally requires a Grant Agreement amendment.
Underspending
Cost-based model: Funding is linked to eligible expenditure, so unspent budget is generally not reimbursed.
Lump sum model: If a work package is successfully completed, the consortium receives the full lump sum, even if the actual costs are lower than initially estimated.
Partial Delivery
Cost-based model: Partners can normally claim reimbursement for eligible work already completed.
Lump sum model: If a work package is only partially completed, payment may be reduced or withheld depending on the extent of non-delivery.
Budget Justification
Cost-based model: Budgets are justified at partner level through individual cost categories.
Lump sum model: Budgets are justified at work package level by explaining the activities, effort, personnel, equipment, travel, subcontracting, and other resources required.
Internal Financial Management
Cost-based model: Financial management focuses on monitoring expenditure across cost categories.
Lump sum model: Financial management focuses on ensuring each work package is fully delivered within its agreed budget.
Primary Financial Risk
Cost-based model: The greatest risk is claiming ineligible costs or exceeding the available budget.
Lump sum model: The greatest risk is failing to complete a work package, which can result in the loss of the associated payment.
The Key Difference
The difference between the two models can be summarised in one sentence:
Cost-based projects reward eligible expenditure.
Lump sum projects reward successful delivery.
How the Lump Sum Budget Is Structured in Your Proposal
Under the lump sum model, your budget is no longer organised around cost categories for each partner.
Instead, it is organised around work packages.
Each work package is assigned a fixed EU contribution during proposal preparation. This amount is agreed during Grant Agreement preparation and remains fixed throughout the project unless the Grant Agreement is formally amended.
Each work package budget should reflect the resources required to complete the planned activities and deliver the agreed outputs.
What a Work Package Budget Includes
A typical work package budget may include:
Personnel effort across all participating partners
Equipment required to complete the work
Travel and meeting costs
Subcontracting, where justified
Other direct costs necessary for implementation
The budget should be proportionate to the complexity, duration, and scale of the activities described in the work package.
Every Work Package Is a Commitment
Each work package represents a commitment between the consortium and the European Commission.
When preparing your proposal, you are effectively stating:
"This work package can be successfully delivered using the resources requested."
Once the Grant Agreement is signed, the agreed lump sum becomes the amount associated with delivering that work package.
This means the budget should not be viewed as an estimate of expected expenditure, but as the agreed value of successfully completing the work package.
Why This Matters
Because payment is linked to work package completion rather than individual cost claims, every work package budget must be credible and fully justified.
If the requested budget appears inconsistent with the proposed activities—for example, a technically demanding work package with very few person-months or a simple coordination work package consuming a disproportionate share of the budget—evaluators are likely to question the realism of the proposal.
The budget, work package description, person-month allocation, deliverables, and timeline should all reinforce one another.
A Practical Rule
Think of each work package as a self-contained project.
It should have:
Clearly defined objectives
Well-described activities
Appropriate resources
Realistic person-month allocations
Meaningful deliverables and milestones
A budget that reflects the work required
If those elements are consistent, the work package budget will usually appear credible to evaluators.
The budget justification narrative
While lump sum removes the need for itemised cost reporting during the project, it does not remove the need to justify your budget in the proposal. Evaluators and project officers will flag WP budgets that appear disproportionate or insufficiently explained. For each WP, your Part B narrative should describe the activities, the effort required, and why the lump sum is appropriate. A strong WP budget justification covers four components:
Personnel effort: who will do the work, how many person-months per partner, and how that effort maps to the tasks
Travel and fieldwork: number of events, site visits, consortium meetings, and conferences — with a cost estimate
Equipment and materials: what needs to be purchased, at what quantity and estimated unit cost
Subcontracting: what is being subcontracted, to what type of provider, and why this capability is not available within the consortium
Practical tip
Build your lump sum budget bottom-up: estimate actual costs (person-months x rates, travel, equipment) in a working spreadsheet first, then translate the total into a WP lump sum. Keep this document — you will need it during GA negotiation when the Commission proposes reductions, and it is your primary tool for defending your numbers.
The Financial Risk Implications
The lump sum model fundamentally changes the nature of financial risk.
Under the cost-based model, the primary concern was overspending or claiming ineligible costs. Under the lump sum model, the greatest financial risk is failing to deliver a work package. Because payment is linked to completed work packages rather than eligible expenditure, delivery becomes the project's most important financial objective.
Delivery Becomes the Financial Priority
Under the lump sum model, work package completion drives payment.
This means that project managers should focus less on monitoring expenditure and more on ensuring that activities, deliverables, and milestones remain on schedule. A delayed or incomplete work package can have direct financial consequences, even if expenditure has been perfectly managed.
Think About Delivery Risks
Your risk analysis should therefore focus on the scenarios that could prevent a work package from being completed.
Examples include technical failures, delayed pilot implementation, regulatory approvals, difficulties recruiting stakeholders, or dependencies between work packages. These are far more relevant than generic risks such as "project delays" or "technical problems."
Practical Tip
When preparing your risk table, ask one simple question:
"What could prevent this work package from being successfully completed?"
The answers will usually reveal the risks that matter most.
Adapting Your Proposal Writing Strategy
The lump sum model requires a different way of thinking during proposal preparation.
Instead of building the proposal around partner costs, build it around work packages and successful delivery.
Justify the Budget at Work Package Level
Your budget justification should explain why each work package requires the requested resources.
Describe the activities, person-months, equipment, travel, subcontracting, and other resources needed to complete the work package—not simply how much each partner will spend.
Design Work Packages Around Deliverables
Each work package should have a clear purpose, a logical scope, and a well-defined endpoint.
Evaluators should be able to determine objectively whether the work package has been completed based on its deliverables and milestones.
Write Better Deliverables
Deliverables should demonstrate what has been produced rather than simply summarising activities.
Reports, validated methodologies, software releases, datasets, guidelines, and prototypes are generally much stronger than activity summaries because they provide tangible evidence that the work has been completed.
Preparing for Grant Agreement Negotiation
Receiving a positive evaluation is not always the end of the budgeting process.
During Grant Agreement preparation, the Commission may ask for clarification or propose adjustments to work package budgets if they appear inconsistent with the planned activities.
Be Ready to Defend Your Budget
Although the detailed internal budget calculations are not submitted with the proposal, they should always be prepared.
A well-documented spreadsheet showing person-month estimates, travel assumptions, equipment costs, and subcontracting makes it much easier to justify the proposed work package budgets during negotiations.
Key Point
Budget adjustments during Grant Agreement preparation are relatively common. What matters is being able to explain how the work package budget was calculated.
Managing a Lump Sum Project
Project management changes once the project begins.
Instead of focusing primarily on expenditure, coordinators should focus on delivery.
Track Progress, Not Spending
The most important management question is no longer:
"Are we spending according to budget?"
Instead, ask:
"Are we on track to complete the work package?"
Monitoring deliverables, milestones, and delivery risks should become the centre of project management.
Use the Flexibility Within a Work Package
One advantage of the lump sum model is the flexibility to manage resources within a work package.
As long as the agreed work package is successfully completed, the consortium has considerable freedom in how resources are used internally. However, moving budget or activities between work packages generally requires a formal amendment to the Grant Agreement.
Five Common Lump Sum Mistakes
Many proposals make the same avoidable mistakes.
The most common are:
Treating a lump sum proposal like a traditional cost-based proposal.
Writing vague or unverifiable deliverables.
Allocating work package budgets without preparing an underlying cost estimate.
Focusing the risk analysis on generic project management risks instead of delivery risks.
Assuming budgets can be freely transferred between work packages after the project starts.
Avoiding these mistakes will significantly strengthen both your proposal and your project's implementation.
Final Thoughts
The lump sum model rewards well-designed projects.
Clear work packages, realistic budgets, meaningful deliverables, and effective risk management not only improve proposal quality but also make projects easier to manage once funded.
Ultimately, successful lump sum proposals are built around one principle:
Design work packages that can be delivered, verified, and confidently defended from proposal submission through to project completion.
Preparing a lump sum proposal and want expert support?
SublimeHub supports consortia with lump sum budget design, WP structuring, budget justification narratives, and full proposal development.
