Holds & Authorizations

These scenarios explain why a customer's available balance can differ from what they expect to be charged.

Car Rental Holds

For car and vehicle rentals, an additional hold is automatically applied at authorization. This is applied on the Wirex side, not by the merchant.

Why: rental transactions often incur secondary charges (fuel, traffic fines, damage, late returns). The hold is a buffer to cover adjustments and prevent a negative balance.

Field	Detail
Affected MCCs	7512 — Automobile Rental, 7519 — Truck / Utility Trailer Rentals
Hold amount	~20% on top of the authorized amount

Settlement: when the merchant sends clearing, the system compares it to the authorization. If clearing < authorization, the excess is released to the customer; if clearing > authorization, the difference is charged. The 20% hold is released as part of clearing — automatically, no manual action.

Fuel Pre-Authorizations (AFD)

Automated Fuel Dispensers (pay-at-pump terminals) send a pre-authorization before the fuel amount is known — standard industry practice.

Field	Detail
Pre-auth hold duration	Up to 32 days
Typical pre-auth amount	A fixed amount set by the merchant (commonly €1 / £1, or larger e.g. €99 / £99 on some networks)

Lifecycle: card inserted → pre-auth hold placed → fuel dispensed → merchant sends clearing for the actual amount → hold released and replaced by the final charge. If clearing is not received within 32 days, the pre-auth hold expires and is released automatically.

Customer says	Explanation
"My balance dropped but I only spent €20"	A larger pre-auth was held initially; it adjusts to the actual amount once clearing arrives.
"The hold has been there for weeks"	If clearing hasn't arrived, the pre-auth expires after 32 days and funds are released.
"I was charged €99 but only fuelled €35"	€99 is a pre-auth hold, not a final charge; it adjusts to €35 once the merchant sends clearing.

AFD holds of up to 32 days are by design and cannot be released manually before expiry unless clearing is received.

Force Debits

A force debit occurs when a transaction is approved and cleared even though the balance is insufficient at settlement, resulting in a negative balance.

A common example is TFL (Transport for London) — transactions are processed offline and submitted for clearing after the journey. By the time the charge clears, the balance may be insufficient. Since the transaction already occurred, it cannot be declined retroactively.

Force debits are initiated by the card network or merchant, not by Wirex. The transaction is received and processed as submitted — it cannot be blocked or reversed at that stage.

Top-up requirement: there is no minimum. Even a $2 negative balance must be topped up. The card is restricted while the balance is negative.

Step	Action
1	Contact Wirex support — they identify the transaction that caused the negative balance and provide the exact top-up amount.
2	Inform the customer of the required amount and have them add funds.
3	Once topped up, notify support to confirm the balance is restored.
4	Wirex processes the debit and the card is unblocked automatically.

Related: an additional debit after a chargeback is a different mechanism — see Chargebacks & Refunds.