Rental glossary

Plain-English definitions of the car & vehicle rental terms operators deal with daily — deposits, waivers, fleet metrics, and the local payment methods used across Thailand, Vietnam and beyond.

Bookings & availability

Reservation

A confirmed booking that holds a specific vehicle for a customer over set pickup and return dates. A reservation should lock that vehicle’s availability so it can’t be booked twice.

Availability

Whether a given vehicle is free to rent for a date range. Real-time availability across every channel (online, walk-in, chat) is what prevents double-bookings.

Double-booking

When the same vehicle is reserved by two customers for overlapping dates — usually because availability wasn’t shared in real time. It forces a cancellation, refund, or last-minute swap.

No-show

A customer who books but never arrives to pick up the vehicle. Deposits and automatic reminders are the usual ways to reduce no-show losses.

Online booking

Letting customers reserve and pay for a vehicle themselves through a web page or link, 24/7, instead of every booking going through a manual message or call.

Payments & deposits

Security deposit

A sum held against potential damage, fuel, fines, or late return, refunded after the vehicle comes back in order. It can be charged or pre-authorized on a card or via local rails like PromptPay.

Pre-authorization (pre-auth)

A temporary hold placed on a customer’s card for the deposit amount without actually charging it. The hold is released on return if there’s no damage, avoiding a real charge and refund cycle.

Deposit hold

The active block of funds (via charge or pre-authorization) covering the security deposit during a rental. It’s released or refunded once the return inspection passes.

PromptPay

Thailand’s instant bank-transfer system using QR codes or a phone/ID number, with no card fees. Widely used for rental payments and deposits by walk-in customers in Thailand.

MoMo

A leading Vietnamese mobile e-wallet for instant payments via QR or phone number. Common for taking rental payments and deposits from local customers in Vietnam.

Commission

A per-booking cut taken by a platform or marketplace. A 0%-commission model means the operator keeps the full rental revenue and isn’t charged on each booking.

Contracts & legal

Rental agreement

The contract between operator and customer covering vehicle details, rates, deposit, insurance, mileage, and return terms. A bilingual, digitally-signed agreement is easier to enforce in a dispute.

Collision Damage Waiver (CDW)

An option that limits the customer’s financial responsibility for damage to the rented vehicle, usually down to a fixed excess. It’s a waiver of liability, not strictly insurance.

Excess (deductible)

The capped amount a customer still pays toward damage even with a waiver or insurance in place. A lower excess means less risk for the customer and is often an upsell.

Liability insurance

Cover for damage or injury the renter causes to third parties (other people, vehicles, or property). It’s distinct from a damage waiver, which covers the rented vehicle itself.

Damage waiver

A general term for an add-on that reduces the customer’s liability for damage to the vehicle in exchange for a daily fee, typically leaving only the excess payable.

Mileage limit

A cap on the distance included in the rental rate, beyond which a per-kilometre charge applies. Unlimited mileage removes the cap and is a common selling point.

Operations & fleet

Fleet

The full set of vehicles an operator rents out. Fleet management covers tracking each vehicle’s status, location, maintenance, and earnings.

Turnaround time

How long it takes to get a returned vehicle cleaned, inspected, and ready to rent again. Shorter turnaround means higher utilization and revenue.

Handover (check-in)

Giving the vehicle to the customer at pickup — verifying ID and licence, signing the agreement, recording condition and fuel, and collecting the deposit.

Return inspection (check-out)

Examining the vehicle when it comes back to log fuel, mileage, and any new damage against the handover record before releasing the deposit.

Telematics / GPS tracking

In-vehicle hardware that reports location, mileage, and usage. It helps recover vehicles, verify mileage, and monitor utilization across the fleet.

Business metrics

Utilization rate

The share of available days a vehicle is actually rented — for example, rented 21 of 30 days is 70%. It’s the core efficiency metric for a rental fleet.

Average Daily Rate (ADR)

Total rental revenue divided by the number of rented days — the average price earned per vehicle per day. ADR and utilization together drive revenue.

Dynamic pricing

Adjusting rental rates by demand, season, day of week, or how much of the fleet is booked, instead of a single fixed price. Done well, it lifts both utilization and ADR.