Acquiring

Merchant ID (MID)

Also: MID

A unique identifier issued by an acquirer that ties transactions to a specific merchant account.

A MID is the merchant's identity at the acquirer. High-volume or multi-region merchants often hold multiple MIDs across acquirers, for redundancy, regional optimisation, or risk segmentation. Smart routing distributes traffic across MIDs based on cost, approval rate, and capacity.

Related terms

Acquirer

The licensed bank or financial institution that holds the merchant's MID and settles card transactions on the merchant's behalf.

Smart routing

Algorithmic selection of an acquirer or MID per transaction to maximise approval rate, minimise cost, or both.

Get started

Ready for velocity?

Tell us about your business. We'll match you with the right acquiring partners and the right route, typically inside a week.

Apply now Explore the platform