Travel is one of the smallest lines in an SBIR budget and one of the most frequently trimmed, because applicants write it as a lump sum with no destination and no purpose. Federal travel costs are allowable when the trip is necessary to the funded work, the rates follow a published framework, and the paperwork proves both. Everything else is a negotiation you will lose.
What counts as allowable travel
The trip has to serve the project. Travel to a collaborator's lab, to a test facility, to a customer or end-user site for the discovery work that supports commercialization, and to the agency's own program meetings is straightforward to justify. Travel that mainly serves business development or general company promotion is not, and marketing travel is usually unallowable outright.
Conference travel sits in between. It is allowable when the meeting is technically relevant and you say why: whose work you need to see, what you will present, which part of the work plan it informs. Some agencies expect and even require attendance at a program or grantee meeting, and a few reserve funds for it. Name the conference or describe the type, state the number of travelers and trips, and connect it to a task. Vague conference lines get cut. If the trip is really customer discovery, say so and tie it to the commercialization plan.
Per diem: published, and specific to where you are going
The federal government publishes per diem rates for lodging and for meals and incidental expenses. Rates are set per location — a city, a county, or a standard rate for everywhere not separately listed — and they are revised on an annual cycle, with some destinations carrying seasonal variation. Foreign and non-contiguous destinations are published separately.
Two practical consequences. First, never invent a number: look up the destination in the current published tables when you build the budget, and note in the justification that the figures came from there. Second, lodging is normally reimbursed at actual cost up to the published ceiling, excluding taxes, while meals and incidentals are paid at the flat daily rate, typically reduced on the first and last day of travel. Your own written travel policy can be more restrictive than the federal rates; it cannot be more generous and still charge the difference to the award.
Air travel and documentation
Coach or economy class is the baseline. A premium fare needs a specific, documented reason — a medical requirement, a route with no coach availability, an unreasonable total travel time — and "it was a long flight" is not one. For foreign travel funded by a federal award, the Fly America Act requires a US flag air carrier or a qualifying code-share, with narrow exceptions under Open Skies agreements. Book the flight before you assume an exception applies, and you will regret it.
Keep the itinerary, the lodging receipt, the traveler names, the business purpose, and the link to the project task. Reconstructed travel records are the kind of thing that turns up badly in a later review, alongside the reporting obligations described in grant reporting and milestones. The wider budget context is in budget mistakes that sink an application and the application guide.
This is general information, not accounting advice; check current rates and your agency's terms with your CPA. Projects House works with founders on the technical plan those trips have to support — the contact form reaches us.