Budget justification is the section most applicants write last, in a rush, and it is the section experienced reviewers scan first when looking for reasons to recommend a cut. A budget that does not read as deliberate invites a "this is inflated" flag that costs you money even when the science is funded. A few patterns separate budgets reviewers believe from budgets they quietly reduce.
Tie every cost to a work package
The single most effective change is to reference the work package or deliverable each cost supports. "PhD student (36 months) for WP2, sequencing and analysis" is credible. "PhD student" is not. If a reviewer cannot quickly map a cost to a specific activity in the plan, the cost looks optional — and optional costs get cut.
Avoid round numbers — they signal "made up"
Budgets full of round numbers (€50,000 for equipment, €10,000 for travel) are a soft tell that no actual sourcing happened. Get real quotes for equipment and cite them. For consumables, reference the cost-per-sample and the number of samples. Reviewers who have written grants themselves can smell a padded budget at 20 paces.
Personnel: justify the FTE, not just the headcount
If you are hiring a postdoc at 100% FTE, explain why the work requires a full-time postdoc rather than a shared one. If you are budgeting for 20% of your own PI time, describe what that 20% covers — supervision, analysis, writing — and link it to specific deliverables. Reviewers are particularly suspicious of PI "salary recovery" with no narrative.
Equipment: first time or cost-share
Large equipment requests trigger the "does your institution not already have this?" question. If you are requesting a shared resource, explain why it cannot be accessed through the institution's existing infrastructure. If you have a cost-share commitment from the host institution, cite the commitment letter explicitly. If the equipment exists at a core facility, budget for core facility access rates instead — it is cheaper and more credible.
Travel: be specific
Line-item travel: "two conferences per year at €1,500 each = €3,000/year". Do not lump travel into a general line. Specific travel with named venues or conferences reads as planned work; a "travel: €15,000" line reads as a slush fund. The same applies to open access publication fees — budget 2–3 OA papers at the actual journal cost, cited.
Checklist
- ✓Every cost line references the work package or deliverable it supports.
- ✓No round numbers on equipment — real quotes with vendor names.
- ✓Personnel FTE is justified with a one-sentence activity description.
- ✓Travel broken into named conferences or destinations.
- ✓Open access fees are line-itemed at actual journal APCs.
- ✓PI time (if recovered) is tied to specific supervision / writing tasks.
- ✓Consumables use cost-per-sample × sample-count, not lump sums.
- ✓Subcontracts and core facility access are at published rate cards.