What is a lowest logical fare (LLF) and how does it work?
The Lowest Logical Fare (LLF) is your company-wide ranking algorithm for flight and hotel search results. Rather than simply listing the cheapest options, LLF balances multiple factors such as cost, duration, comfort, and brand loyalty, to surface the “best” choices that fit your travel policy.
As an admin, you can adjust the Lowest Logical Fare to be better aligned with your business travel objectives. This will impact two things:
- The default sorting of search results presented to bookers. For example if you prioritise budget & cost, low cost airlines might show up as the first result.
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The recommended alternatives that we share with approvals and store in fare comparison (cost savings report). For example if you prioritise budget & cost, we will consider low lost airlines a good alternative and potentially cost saving that has been missed.
When should you adjust your LLF?
Most companies never need to change the default. But tweaking LLF can help when your priorities shift towards a certain direction. Some examples below
| Scenario: | You can optimise flight results to: |
|---|---|
| You need to meet aggressive budget targets | Drive down per-traveller costs, even if it means longer connections or fewer amenities. |
| You have more executive or last-minute travel | Prioritize minimal layovers, convenient flight times, and higher-rated hotels to keep senior staff rested and productive. |
| Seasonal or Peak-Period Booking | During high-demand seasons (e.g., holidays, major conferences), lean harder on cost controls to avoid surcharges. |
| Sustainability Initiatives | If you’re offsetting carbon or aiming to reduce emissions, give extra weight to itineraries with fewer stops. |
Tip: If you’re unsure, start with one of our presets (below) and fine-tune individual sliders later.
To change your LLF settings, you can simply:
- Go to Company Settings -> Lowest Logical fare (https://app.trutrip.co/company/lowest-logical-fare).
- Select the Lowest Logical Fare tab.
- Edit the LLF for flights or hotels.
- Save your settings—these will immediately apply for all company travelers and all future searches.
1. Adjusting the default search logic for flights and hotels
When adjusting the default search logic for flights or hotels, you'll find some default presets at the top that you can chose from, or you can customise in more detail.
| Flights | Accommodation |
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Customising the search logic
For more advanced adjustments, you can click on "Custom" and tweak every component manually by setting the importance from 1 - 5.
The combination of your priorities will influence all search and comparison results. Things you can adjust:
| Flights | Accommodation |
|
|
Example of what it looks like when searching for flights. On the left: duration is set to very important, cost to not important. On the right: duration is not important, cost is very important.
The first 5 results are still balanced based on a mix of cost and duration, but as you can see the Qatar flights do save about 300SGD compared to the KLM direct flight.
2. Configuring the "best alternatives" available for flights
When people search and select flights or hotels, the system stores the best alternative fares that are available during that search. During approval and analysis, we use these alternative fares to inform managers and admins. Learn more in fare comparisons & benchmarks.
In the lowest logical fare configuration for flights you can define, on a company level, what is considered a "good alternative" based on flight departure times (this only applies to return flights at the moment).
How this works:
As you can see, we categorise flight bookings down into short (< 3 days) , medium (3-7 days) and long trips (7+ days) with default preset time deviations based on departure time. For all these trip types, you can adjust if alternatives departing earlier or later are considered acceptable or not.
Example: the departure time deviation for a short trip is set to -2 and +4 hours
A booker selects a flight that departs on Tuesday 08:55, and returns on Wednesday 18:30.
The recommendation config will only look for any relevant alternatives that depart at maximum 2 hours earlier or 4 hours later then Tuesday 08:55 and Wednesday 18:30.
When a manager approves the booking or runs a cost-saving report later, they will only see alternatives in this time frame