Lowest Logical Fare (LLF)

The cheapest fare that still meets policy and practical needs — routing, timing and preferred suppliers. It's not simply the lowest price available, but the lowest price among options that satisfy the traveller's reasonable schedule and the company's policy constraints. Booking tools often use LLF as the benchmark for judging whether a chosen fare falls within policy.

To calculate the LLF, a booking tool applies a set of reasonable parameters to the traveller's search: a time window around the preferred departure, a maximum number of connections and total journey time, sometimes a list of preferred airlines or nearby airports, and the cabin allowed by policy. The cheapest fare that meets all of these conditions becomes the benchmark. If the traveller chooses a more expensive option, the difference can be recorded and, in some programmes, explained with a reason.

The strength of LLF is that it sets a fair and realistic standard. The absolute lowest fare on a route might involve two connections, an overnight wait or a departure at 5 a.m. — options no company would reasonably expect an employee to take. By comparing each booking against a logical alternative instead, travel managers get meaningful data on savings and missed savings, and travellers are not pushed into unreasonable itineraries just to save a small amount.

Tumodo's travel policy settings follow the same logic. Companies can set the maximum deviation from the minimum cost, define route price limits, limit the number of connections and flight duration, and specify acceptable departure times. Options that fall outside these rules are flagged automatically, and a price calendar helps travellers find the most cost-effective day to fly. Tumodo's analytics also show price trends and savings opportunities, helping companies refine their rules over time.