A useful rate is more than a dollar amount. It needs a destination, a date, a boundary and a source you can check.
Our data process
We import the published GSA master workbooks and ZIP workbooks for FY2026 and FY2027. Original files are preserved with retrieval timestamps and SHA-256 hashes. The source manifest identifies exactly which files the directory uses.
The importer checks every seasonal interval for gaps and overlaps, then verifies all twelve monthly values and the meal rate in every ZIP row against the master file. It keeps multiple ZIP matches and missing source fields visible. It does not add rates from commercial directories or infer a missing locality from a neighboring one.
Identity and year-to-year comparisons
GSA DestinationID links records across editions. Each year keeps its original name and county definition. Our changes explorer includes non-standard areas whose coverage wording is identical, plus an explicit standard CONUS option. Compare the same fiscal month or select the separately labeled annual maximum; an annual maximum need not occur in the same month in both years. A revised name is not automatically classified as a new place; a changed boundary is not assumed to describe the same area.
How the calculator works
Calculations use integer cents and calendar dates. Each overnight date selects its fiscal year and monthly lodging ceiling. The return date has no hotel night. First and last meal days receive 75% before the full allocated value of deductible meals is subtracted. The incidental allowance is retained. We apply the rules to a single qualifying work locality and exclude personal days, agency exceptions, lodging taxes and other trip expenses.
A per-night room price overrides the default price for that date. A blank price uses the default, or the published ceiling when the default is also blank. Zero is an explicit no-cost night. Each quoted night is capped independently; excess above the ordinary limit is reported separately and is not offset by cheaper nights. Estimates containing both quoted prices and unknown prices are labeled as mixed.
Calculated budgets are not approvals or tax conclusions. The input, daily arithmetic and source years appear in the output and CSV.
State tax reference
We summarize 49 GSA SmartPay state pages, retaining the source URL, retrieval timestamp and checksum. Each page distinguishes individually and centrally billed arrangements, forms and the conditions actually stated by the source. An unlisted form is not treated as a statement that no form is required. Tax guidance follows the hotel’s jurisdiction; a per diem locality spanning state lines does not create one shared tax jurisdiction. Official linked documents may change after the snapshot.
Editorial process
The explanations and examples are original content prepared with AI assistance and checked against the listed official publications. We do not claim independent professional review or personal travel experience. Rate facts, worked examples and interpretation are kept distinct.
The source review date is October 1, 2026. Rebuilding a page does not update that date or imply that the source was checked again.
Updates and corrections
Data updates require downloading the new official files, reviewing differences, running validation and reviewing the resulting pages. This preview does not run an automatic live feed. Rates outside the included period are rejected by the calculator. A future edition must pass the same checks before becoming available.
Inspect the sources and downloads or prepare a correction report.