The short answer
A dedicated MID is a 15-digit merchant identification number assigned by an acquiring bank to one specific merchant. Visa and Mastercard see that merchant as an individual merchant of record. Chargeback ratios are calculated against that merchant's volume in isolation, reserves are sized to that merchant's profile, and funding flows from the acquirer directly to the merchant's bank account. It is the opposite of an aggregated MID, where one master MID pools many sub-merchants' volume.
How you get one
A dedicated MID comes from an acquirer — Chase Paymentech, Wells Fargo Merchant Services, Worldpay from FIS, Elavon, FirstData/Fiserv, Global Payments, WorldPay, and roughly two dozen smaller regionals. Underwriting requires a full application (EIN, articles of incorporation, voided check, two years of bank statements, processing history if existing, projected volume, MCC declaration). Turnaround is 24 hours (clean, low-risk) to 3 weeks (high-risk vertical requiring specialist acquirer placement). ISOs can introduce you and manage the relationship; multiflow operates this way for parent merchant accounts.
What operators need to know
- Pricing is almost always interchange-plus. Your true card-cost (0.80% on debit, 1.65% on regulated credit, 2.40% on premium rewards) passes through with a transparent markup on top (typically 15–35 bps for clean commerce, 50–150 bps for high-risk). Savings vs. flat-rate PayFac pricing are 50–150 bps at volume.
- Chargeback ratio is yours alone. Not contaminated by other merchants' behavior. If you run clean, you stay clean. This is especially important in borderline-risk verticals where an aggregated MID's portfolio ratio can trip Visa VAMP thresholds unrelated to your own performance.
- Reserve structures are negotiable. Rolling reserves (e.g., 5% of gross held for 180 days) and upfront reserves are line-items in your merchant agreement, not imposed unilaterally by a PayFac.
- Descriptors are clean. No "SQ *" or "PYPL *" prefix. Your soft descriptor shows on bank statements as your brand, full stop. Measurable reduction in "I don't recognize this charge" disputes.
- Funding is direct from the acquirer. Daily ACH into your bank account at the acquirer's payout schedule (usually T+1 or T+2 for domestic card-present, T+2 or T+3 for card-not-present). No PayFac payout-schedule layer.
- Offboarding risk shifts. Termination requires acquirer-level risk review. Far less trigger-happy than PayFac account closures but higher-consequence when it happens (typically 30–60 day notice + MATCH list review).
When a dedicated MID is overkill
If you are processing under $20k/month and your vertical is PayFac-friendly (DTC ecommerce in low-risk categories, SaaS, digital goods, subscriptions), the setup friction of a dedicated MID is not justified. Stripe / Square covers you at acceptable economics. The breakpoint is typically $50k/month across a portfolio, or any volume in a vertical PayFacs won't underwrite — peptides, nutra, CBD, firearms, tobacco, adult, gambling. See our pricing tiers for the decision framework.