Trust and scope
Methodology, sources, and disclaimer
ReimburseKit is an informational reimbursement utility site. It is not a tax filing service, legal service, or payroll platform.
Primary sources
- IRS standard mileage rates
- IRS Publication 463
- GSA FY2026 per diem master rates workbook
Last reviewed for this MVP: May 4, 2026.
Calculator behavior
- Mileage tool multiplies miles by the selected IRS rate.
- Per diem tool matches an imported FY2026 GSA CONUS destination, selects the right lodging season by month, then applies 75% on the first and last travel day.
- Standard CONUS is available only as an explicit user choice, not a silent fallback for unsupported destinations.
What this MVP does not do
- Provide individualized tax, legal, or accounting advice
- Maintain official records for you
- Guarantee reimbursement eligibility under your policy or jurisdiction
- Offer live checkout or customer accounts in local development
Update policy
- Review IRS mileage data when the IRS publishes a new annual rate notice.
- Review GSA per diem data at least annually and after any destination-rate source change.
- Re-run `npm run import:perdiem` after replacing the official GSA workbook in `data/`.
- Re-run calculator tests, data checks, and CUJ screenshots after any rate update.