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Cost Comparison Requirements


  1. A cost comparison must:
    1. Be obtained prior to the trip
      1. Best Practice: Comparison should be obtained at the same time the trip is arranged.
    2. Search sites that show results for multiple airlines
      1. Best Practice:  Use Concur to find the comparison
      2. If Concur is not used, an online vendor that shows results from multiple airlines must be used
      3. Search results from a single airline site is not acceptable
      4. Two one-way flights used in place of a round-trip flight is not acceptable
    3. Search based on
      1. The business destination(s) for the dates and times of business
      2. Include the day before business begins and day after business ends as travel days
        1. No personal dates or destinations may be included in the comparison
      3. If a traveler is eligible to purchase a higher class fare, but chooses to purchase economy, the cost comparison should be economy as well.
    4. Select the lowest logical fare as the comparison price
      1. The lowest logical flight generally includes one stopover
    5. Attach the comparison to expense report
  2. A copy of a co-worker's airfare itinerary/receipt that attended the same business event with no personal time or other travel destinations involved.
  3. A written statement from a travel agency obtained prior to the trip.


  • Comparisons are only accurate if obtained 'prior' to travel.
    • Best Practice: Comparison should be obtained at the same time the tickets are purchased.


In the event a traveler has not provided a required comparison, the Business Office or Central Travel Office staff may obtain the cost comparison.


The amount that is reimbursed is the lesser of the cost comparison or actual expense amount.


  1. Driving VS Flying:
    • The mileage reimbursement cannot exceed the lowest logical airfare prior to travel. To qualify for reimbursement when driving longer distances normally accomplished by flying (Rule of Thumb: Greater than 800 miles roundtrip), the expense under the "Drive Vs Fly" rule must be the lesser of the actual mileage expense or total of:
      • Lowest logical economy/coach airfare prior to travel for dates of business only
      • Roundtrip mileage to airport
      • Airport parking ( contracted rate of $9.00 per day)
      • Shuttle expense to/from airport to business location
  2. When leaving from or returning to a location other than 'Official Station' or place of business:
    • Travel expense reimbursement is limited to the lesser of expenses incurred departing from or returning to the "official station" or place of business. The official station is defined as the location of the permanent office.
      • If two adjoining trips are made for University business with no personal travel included, a cost comparison is not required even though the traveler is departing from a location other than the official station to go to the second business location.
  3. When discounted fare that requires additional overnight stay (generally a Saturday night) is purchased:
    • Discounted airfare, additional lodging, fixed meals and any other expenses incurred due to the additional stay must not exceed regular economy/coach fare for the business trip.
  4. When combining personal and business travel:
    • Occasionally an employee may take a trip that includes both personal and business days.
    • When this occurs, the following rules apply.
      • A cost comparison is not necessary if the stay at the business location is extended up to 3 days either prior to or after the dates of the business mission.
      • A cost comparison is required if the stay is extended longer than 3 days prior to or after the dates of the business mission.
        • Additional expenses resulting from the added personal time, i.e., parking, lodging, fixed meals, etc., are not reimbursable.
      • A cost comparison is required when the airfare includes overnight stays at destinations (excepting normal connecting airports) other than the business destination(s). 
        • The traveler must provide a cost comparison showing lowest logical airfare for the direct route to and from the business location for the days of business.
    • A combination trip does benefit the traveler to some extent, therefore, travelers should exercise special care not to seek reimbursement for expenses that could be construed as personal.  Additional information can be found at personal and business travel.
  5. When Using Leased or Chartered Aircraft:
    • The actual lease cost for aircraft leased from a commercial leasing company or Purdue Aero Club is reimbursable up to the lowest logical round trip commercial coach airfare rate for the same trip for the same number of official passengers.
    • Chartered aircraft expenses are reimbursable up to the lowest lodgical round trip commercial coach airfare for the same dates and destination of travel.
    • In each of the situations above, a traveler must provide a written cost comparison.
  6. When Using A Train to Travel in a Foreign Country:
    • A foreign train, bus or other service carrier may be used in lieu of, or as a supplement to air travel at the lowest rate by the transportation facility used.
    • If such travel could have been performed by air, the allowance should not exceed that of the lowest logical coach air accommodations.
  7. When airfare purchased is a higher class than allowed by University travel guidelines.