Fuel Card Management: Controls, Fraud Prevention & Card Comparison

The fraud is not limited to drivers stealing fuel. It includes station attendants processing split transactions to stay under alert thresholds, drivers lending cards to friends and family, and organized skimming operations at high-traffic truck stops. Without the right controls, a fuel card is an open line of credit with almost no spending oversight.

The first and most common type is personal-use fraud: drivers fueling personal vehicles, boats, or equipment on a fleet card. It happens most frequently on weekends and holidays when fleet managers are not monitoring transactions in real time. A single driver fueling a personal pickup twice a week adds $6,000-$8,000 in annual unauthorized charges.

The second type is buddy-fueling: a driver swipes the fleet card for another person's vehicle in exchange for cash at a discount. The transaction looks legitimate — correct fuel type, reasonable gallon amount — but the fuel goes into a vehicle that is not on your fleet roster. This is nearly impossible to catch without GPS-to-transaction matching.

Most fleet managers review fuel card statements monthly — some only quarterly. By the time a pattern surfaces in a spreadsheet, the fraud has been running for 60-90 days. A driver who steals $150 per week in fuel has taken $2,400 before anyone notices. The delay happens because card issuers batch transactions, fleet managers lack automated alerts, and the sheer volume of legitimate transactions buries the anomalies.

Real-time exception reporting changes that timeline from months to hours. WEX, Fuelman, and Coast all offer configurable alerts for transactions that exceed dollar limits, gallon caps, or geographic boundaries. The fleets that catch fraud early are the ones that set those alerts on day one and actually respond to them.

A fleet fuel card is a charge card issued to drivers or vehicles that restricts purchases to fuel and authorized maintenance items at participating fuel stations. Unlike a corporate credit card, fuel cards capture detailed transaction data — gallons pumped, fuel grade, odometer reading, driver ID, and station location — that feeds directly into fleet reporting and accounting systems.

When a driver swipes a fleet fuel card at the pump, the transaction follows a five-step process. First, the point-of-sale terminal sends the card number and merchant ID to the card network (Mastercard for WEX, proprietary networks for Fuelman and Comdata). Second, the network checks the card against the fleet's purchase controls: Is the card active? Is this station authorized? Is the transaction within the dollar and gallon limits? Does the time of day fall within the allowed window?

Third, if the transaction passes all control checks, the network sends an authorization code back to the terminal and the pump activates. Fourth, the pump captures Level III data during fueling — gallons dispensed, price per gallon, product type, and (if prompted) odometer reading and driver ID. Fifth, the completed transaction settles within 24-48 hours, appearing in the fleet's online card management portal with full transaction detail.

This entire process takes 3-5 seconds at the pump. The fleet manager sees the transaction the next business day with enough detail to verify legitimacy — or flag it for investigation.

Level III data is the line-item detail captured during a fuel card transaction: exact gallons, price per gallon, fuel grade (diesel, unleaded, DEF), non-fuel items purchased, and the station's merchant category code. Standard credit cards capture only Level I data (merchant name and total amount) or Level II (adds tax amount and merchant zip code). The difference is the difference between knowing "Driver #42 spent $187 at Pilot" and knowing "Driver #42 pumped 47.3 gallons of diesel at $3.95/gallon at Pilot #2847 in Memphis, TN at 2:14 AM on a Tuesday."

Fleet fuel cards fall into two categories: universal cards accepted at virtually any fuel station, and proprietary cards tied to a specific fuel network. The choice between them depends on your fleet's operating radius, fuel volume, and how much you value discount depth versus station flexibility.

The tradeoff is typically a smaller per-gallon discount. Universal cards offer rebates of 2-8 cents per gallon depending on volume, compared to proprietary cards that can offer 10-15 cents per gallon at network stations. For a truck burning 20,000 gallons per year, that is the difference between $400 and $3,000 in annual savings per vehicle.

The discount math is compelling for regional fleets. Proprietary cards negotiate volume-based pricing with their station networks, passing savings of 5-15 cents per gallon to cardholders. A 30-truck fleet consuming 600,000 gallons annually saves $30,000-$90,000 per year on fuel costs alone at those discount levels. The question is whether your drivers' routes align with the station network. If drivers regularly operate in areas with sparse network coverage, the time and mileage wasted finding an approved station erodes those savings fast.

Several providers now offer hybrid programs. WEX's Mixed Fleet solution lets you issue both proprietary and universal cards to different drivers based on their routes. Comdata's card works as a proprietary card at network truck stops (with full discounts) but can also be used at non-network stations on the Mastercard network (at a lower or zero discount). This hybrid approach gives long-haul drivers the flexibility they need while giving regional or local drivers the cost savings of a proprietary network.

Choosing a fuel card program comes down to four factors: acceptance network, discount structure, fraud controls, and integration capability. Here is how the four major fleet fuel card providers compare as of 2026.

WEX is the strongest choice for multi-state fleets that need universal acceptance and broad software integrations. Fuelman wins on per-gallon discounts for regional fleets with routes that align with its station network. Coast is the best option for small fleets and startups that want no contracts, no fees, and a modern app-first experience. Comdata dominates in over-the-road trucking where its truck stop network — Pilot/Flying J, Love's, TA/Petro — covers the routes long-haul drivers actually run.

Dollar limits set a maximum transaction amount per swipe, per day, or per week. Gallon caps set a maximum number of gallons per transaction. Both controls should be set based on the vehicle's actual tank capacity and typical usage patterns, not rounded up to a comfortable number. A Class 8 truck with dual 120-gallon tanks should have a gallon cap of 250 gallons (allowing for a full fill-up from near-empty). A service van with a 25-gallon tank has no business processing a 60-gallon transaction.

Set dollar limits 15-20% above the expected maximum fill-up cost to account for fuel price fluctuations. At $4.00 per gallon diesel, a 250-gallon cap translates to a $1,000 fill-up. Set the dollar limit at $1,200 to absorb price spikes without triggering false declines that strand drivers at the pump. Review and adjust limits quarterly as fuel prices move.

Time restrictions prevent card use outside of operating hours. If your fleet runs Monday through Friday, 5 AM to 8 PM, there is no reason a fuel card should authorize a transaction at 11 PM on a Saturday. Time-of-day restrictions catch personal-use fraud immediately — the card simply declines. Drivers who genuinely need fuel outside restricted hours can request a temporary override, creating an audit trail.

WEX and Comdata both support time-of-day restrictions at the card level. Fuelman offers time restrictions through its online portal. Coast allows time-based rules through its API. For fleets with drivers in multiple time zones, set restrictions based on the card's assigned time zone, not the corporate office — otherwise a West Coast driver gets declined at 6 PM because it is 9 PM at headquarters.

Product restrictions control what the card can purchase beyond fuel. The tightest setting is fuel-only: the card authorizes diesel, unleaded, or DEF and declines everything else. A looser setting adds maintenance items — oil, coolant, wiper fluid, roadside repairs. The loosest setting allows any product at an approved merchant, which is where fraud risk escalates sharply.

My recommendation: set all driver cards to fuel-only by default. Issue a separate maintenance card or purchase order process for non-fuel items. This eliminates the most common collusion fraud vector where a station attendant codes non-fuel merchandise as fuel. If you must allow maintenance purchases on the fuel card, restrict it to merchant category codes for auto parts and service — not general merchandise or convenience store items.

Geographic restrictions limit card use to specific states, ZIP codes, or a defined radius around assigned routes. Station-level restrictions go further, approving or blocking specific merchant IDs. Both controls are available on WEX, Comdata, and Coast cards. Fuelman's proprietary network acts as an implicit geographic restriction since the card only works at Fuelman-network stations.

Not every driver needs the same controls. Here is a practical framework:

Purchase controls prevent obvious fraud by declining unauthorized transactions at the pump. Exception reporting catches the fraud that gets through — transactions that technically pass every control but still look wrong when analyzed in context. Exception reports compare each transaction against expected patterns and flag deviations for human review.

A tank-capacity alert fires when the gallons purchased in a single transaction exceed the assigned vehicle's tank capacity. If Vehicle #317 has a 50-gallon tank and Driver Johnson just pumped 68 gallons, either the vehicle assignment is wrong in the system or someone fueled a second vehicle on the same card. This is the simplest and most reliable exception report — it requires only accurate vehicle data in your fleet management system.

To set this up, build a vehicle reference table with tank capacity for every unit in the fleet and match it against incoming fuel card transactions daily. WEX and Comdata offer built-in tank capacity alerts in their fleet portals. For other providers, Fleetio and similar fleet management platforms can run this comparison automatically when fuel card data is imported.

Frequency alerts flag drivers who fill up more often than their route and vehicle should require. A truck averaging 6 MPG on a 500-mile daily route burns roughly 83 gallons per day. If that driver is filling up twice in the same day for 80+ gallons each time, the math does not work. Either the vehicle has a fuel leak (a maintenance issue worth catching) or the second fill-up went somewhere else.

Set frequency alerts based on a rolling average. If a driver's fill-up frequency exceeds their 30-day average by more than 50%, flag the transactions for review. Seasonal changes (cold weather increases fuel consumption 10-15% for diesel engines) will shift the baseline, so recalibrate thresholds quarterly.

GPS-to-transaction matching is the most powerful fraud detection tool available to fleets that use both fuel cards and telematics. The process is straightforward: compare the station location where the card was swiped against the vehicle's GPS coordinates at the same timestamp. If the vehicle was 50 miles away from the station when the card was used, someone else used that card.

A fuel card without software integration is a reporting burden. Someone has to download CSV files, import them into spreadsheets, and manually cross-reference transactions against vehicle assignments. That manual process breaks down at around 20-30 vehicles. Beyond that threshold, automated integration between your fuel card provider and fleet management platform is not optional — it is the only way to run exception reports, calculate cost-per-mile by vehicle, and catch fraud in real time.

Direct API integrations pull transaction data from the card provider into your fleet software automatically, typically every 4-12 hours. File-based imports require someone to download a transaction file (CSV or XML) from the card provider's portal and upload it into the fleet platform manually. The difference is the difference between catching a fraudulent transaction the same day and catching it next month.

The real power of fuel card integration is the ability to match every card transaction against telematics data from the same vehicle. This creates a three-way reconciliation: the card says 65 gallons were purchased at Station X at 3:14 PM. The telematics says Vehicle #208 was at Station X at 3:14 PM and its fuel level sensor registered a 62-gallon increase. The 3-gallon variance is within normal tolerance. Everything checks out.

Fleets operating across multiple regions or with diverse vehicle types often end up issuing cards from more than one provider. A fleet with both local service vans in the Southeast and OTR trucks running coast-to-coast might issue Fuelman cards to local drivers (better network discounts regionally) and WEX or Comdata cards to long-haul drivers (universal acceptance). Managing that complexity requires centralized reporting, consistent policies, and a clear driver onboarding process.

Issue multiple card brands when the economics justify the administrative overhead. If your regional drivers can save 10+ cents per gallon on a proprietary card compared to a universal card, and they collectively purchase 300,000+ gallons per year, that is $30,000+ in annual savings worth managing a second card program. Below that threshold, the simplicity of a single universal card usually wins.

Also consider multi-card programs when no single provider covers your full operating geography. A fleet running trucks in both the US and Canada may need a WEX card for domestic operations and a separate Canadian fuel card program. Comdata's cross-border capabilities with its truck stop network partially address this, but coverage gaps still exist in rural Canadian provinces.

Fleet management platforms solve this by acting as the aggregation layer. Fleetio imports data from WEX, Fuelman, Coast, and Comdata into a single fuel management module. Every transaction — regardless of card provider — appears in one dashboard, with consistent exception reporting and cost-per-mile calculations across the entire fleet. For fleets without a fleet management platform, WEX's analytics portal supports multi-brand card data import, but the setup requires working with their enterprise team.

Every new driver should receive their fuel card assignment as part of a documented onboarding process. That process includes: assigning the correct card type based on driver role and route profile, setting vehicle-specific purchase controls before the card is activated, having the driver acknowledge the fuel card policy in writing (what is allowed, what is not, consequences of misuse), and entering the driver-to-card-to-vehicle mapping in both the card provider's system and the fleet management platform.

Card issuance timelines vary by provider. WEX and Fuelman ship physical cards in 5-7 business days. Coast issues virtual card numbers within minutes through its mobile app, with physical cards arriving later. Comdata can issue temporary fuel codes for immediate use at truck stops while permanent cards are in transit. For fleets with high driver turnover, Coast's instant virtual card issuance eliminates the gap between hire date and card activation.

IFTA requires carriers to report total miles driven and total gallons purchased in each member jurisdiction, then reconcile fuel tax owed versus fuel tax already paid at the pump. The filing calculates whether the carrier owes additional tax or is due a refund for each state. Without fuel cards, this process requires manual receipt collection, jurisdiction-by-jurisdiction sorting, and gallon tallying that takes 8-15 hours per quarter for a mid-size fleet.

Some fuel purchases qualify for state or federal tax exemptions. Off-highway fuel use (powering PTO equipment, refrigeration units, or generators) may be exempt from state road-use taxes in certain jurisdictions. Fuel card programs can tag these purchases separately when the fleet configures vehicle-level or driver-level flags for off-highway equipment.

State-level reporting requirements vary. Oregon charges a weight-mile tax instead of a fuel tax, which means fuel purchased in Oregon needs different treatment in IFTA calculations. New York, Kentucky, and New Mexico impose additional state-specific highway use taxes beyond the standard IFTA framework. Your fuel card data provides the raw transaction records, but the reporting logic needs to account for these state exceptions — either through your fleet management platform or your accountant's IFTA preparation software.

Choosing a fuel card is not about finding the card with the biggest rebate headline. It is about matching card capabilities to your fleet's size, route profile, integration needs, and risk tolerance. Here is how to evaluate the decision.

Fleets under 15 vehicles should default to a universal card with no minimum volume requirements. Coast is purpose-built for this segment: no contracts, no minimum fleet size, instant virtual card issuance, and a simple mobile app. WEX's small fleet program works for fleets as small as 5 vehicles but comes with more traditional contract terms.

Fleets with 15-100 vehicles have the most options. If your drivers operate primarily within a defined region, proprietary cards from Fuelman or Comdata deliver meaningful per-gallon savings. If drivers cross state lines regularly, WEX or a hybrid program avoids the route-planning hassle of limited station networks. Fleets over 100 vehicles should negotiate custom pricing directly with WEX or Comdata — published rack rates do not apply at that volume, and discounts of 10-20 cents per gallon are negotiable.

Fuel card discounts come in two structures. Cents-per-gallon discounts reduce the pump price by a fixed amount — you pay $3.85 instead of $3.95. These discounts are common on proprietary cards and typically range from 3-15 cents per gallon depending on volume tier. Rebate-tier programs refund a percentage of total fuel spend at the end of the billing cycle — typically 2-6% for universal cards.

Cents-per-gallon discounts are more transparent and immediately visible on each transaction. Rebate tiers can be more lucrative at high volumes but often come with conditions: minimum monthly gallons, maximum per-transaction amounts, or exclusions for certain fuel types. Read the fine print. A 6% rebate that only applies to the first $50,000 in monthly fuel purchases is worth less than a flat 4-cents-per-gallon discount on unlimited volume for a large fleet.

Fuel card contracts often include fees that do not appear in the sales pitch. Common hidden costs include: card replacement fees ($5-$15 per card), monthly minimum volume fees ($50-$200 if you fall below a monthly gallon threshold), out-of-network transaction fees (on proprietary cards used at non-network stations), early termination fees (up to $500 per card on multi-year contracts), and paper statement fees ($5-$10/month if you do not opt for electronic billing).

Before signing, request a complete fee schedule — not just the marketing summary. Compare the total cost of the program (annual fees + per-card charges + potential penalty fees) against the projected fuel discount savings. A card that saves 8 cents per gallon but charges $3/card/month for 50 cards costs $1,800 per year in card fees alone. If those 50 cards collectively purchase 250,000 gallons, the gross savings are $20,000, netting $18,200 after card fees. That math works. But for a 10-truck fleet purchasing 50,000 gallons, the same $1,800 fee against $4,000 in savings leaves a much thinner margin.