Acquirer, Processor, Gateway, ISO, PayFac: Who Does What on a MID
The five parties behind a US merchant account, and which one underwrites you, moves your money, runs your checkout, sells the account or boards you under its own MID.
The acquirer underwrites you, issues the MID, holds the reserve, settles your funds and can terminate the account. The processor carries the authorization and settlement messages; the gateway is the checkout software that sends them. An ISO sells the account and manages the relationship but approves nothing and holds no money. A PayFac boards you under its own MID and can close you on its own terms; an IBO package is built for a dedicated MID.
Five parties stand between your checkout and your bank account, and each does one job. The acquirer is the bank that holds your merchant account: it underwrites you, issues the MID, holds the reserve, settles your funds and can terminate the account. The processor carries authorization and settlement messages between your gateway, the card networks and the acquirer. The gateway is the checkout software that captures the card and sends the request. The ISO sells you the acquirer's account and manages the relationship, but approves nothing and holds no money. The PayFac replaces the chain for small merchants by boarding them under its own MID, on its own terms. This guide covers what each party decides, what it cannot, and who to call when something breaks.
| Party | Underwrites you | Holds your money | Runs the checkout | Can end the account |
|---|---|---|---|---|
| Acquirer | Yes, and issues the MID | Yes: settlements, reserve, holds | No | Yes, and can report to MATCH |
| Processor | No | No, it moves the messages | No | No, but an outage stops authorizations |
| Gateway | No | No | Yes | No |
| ISO | No, it pre-screens and submits | No | Sometimes, as a reseller | No, it relays the decision |
| PayFac | Yes, as its sub-merchant | Yes, until it pays you out | Usually, its own | Yes, on its own terms |
The acquirer: the bank that underwrites, settles and terminates
The acquirer, or acquiring bank, is a member of the card networks licensed to accept card payments on behalf of merchants. Your merchant account lives there. Before opening one, the acquirer underwrites you: KYB on the entity, KYC and a credit pull on the authorized signer and personal guarantor, a review of the website, the projected volumes and the ticket size, and a verification call with the signer. When the file clears, the acquirer issues the MID, the identifier of your merchant account, and you sign a merchant agreement naming the acquirer as the bank of record, even when the ISO that sold the account is also on the paperwork. That agreement fixes the fees, the reserve, the processing cap and the termination clauses. The underwriting guide on this blog walks through each check.
Everything that touches your money is the acquirer's decision. It receives the funds the issuing banks release through the networks, deducts its fees and the reserve, and pays the balance to the account of record, which must belong to the applying entity. It sets the rolling reserve and the monthly cap. Its risk team decides to hold a settlement, lower the cap or terminate the MID, and a termination for one of the listed reasons can place the merchant on MATCH, the file other acquirers query before boarding. An ISO can argue on your behalf; it cannot overrule the acquirer.
KYB also asks who owns and controls the entity. That is the acquirer's own question, separate from FinCEN beneficial ownership reporting; at the time of writing, under FinCEN's interim final rule of March 2025, domestic companies and US persons are exempt from BOI reporting while companies formed under foreign law that register in a US state remain subject to it. Verify current FinCEN guidance and let a professional decide what applies to you; IBOCore gives no legal or tax advice. In an IBOCore package, the documents show the director on the state filing and on the EIN letter.
The processor: the platform that moves the messages
The processor is the technical platform that routes a transaction. When your gateway sends an authorization request, the processor forwards it through the card network to the issuing bank, returns the approval or decline, and later batches the captured transactions for clearing and settlement. Some acquirers run their own platform; others operate on a third-party processor that may serve many acquirers. You rarely choose it separately; it comes with the acquirer. The processor does not underwrite you and does not own your funds. What it owns is uptime and response codes. When every card declines with the same technical code, or a batch does not close, the fault is usually here or at the gateway, and your ISO or the acquirer's support desk opens the ticket.
The gateway: the checkout software that talks to the processor
The gateway sits between your store and the processor. It captures the card at checkout, tokenizes it, builds the authorization request, sends it to the processor over the credentials tied to your MID and returns the response to your store. It stores the tokens behind recurring billing, and many gateways add 3-D Secure, velocity rules and fraud screening. A gateway holds no money and underwrites nobody. It can come from the acquirer or the ISO, or be chosen independently and pointed at any MID it supports. That separation is why a terminated MID does not force you to rebuild your checkout: the integration stays in place, with nothing to send to until a new MID sits behind it.
The applicant behind the MID, ready the same day
An IBOCore package supplies the US entity, the director who signs and takes the call, the bank account and the documents. Browse the inventory page or ask on Telegram.
The ISO: the party that sells the account and manages the relationship
An ISO, an independent sales organization, is registered with the card networks through one or more sponsoring acquirers, sells those acquirers' merchant accounts and manages the merchants it brings in. Mastercard calls the role an MSP; agents work under ISOs. The ISO pre-screens your business against the appetite of each acquirer it represents, packages the application, submits it to underwriting and relays pends and the decision. After approval it is your day-to-day contact for pricing, statements, cap increases and questions. What it cannot do matters as much: an ISO may review the file before the acquirer sees it, but it does not give the final approval, does not hold your money and cannot release a reserve on its own. Every one of those answers comes from the acquirer, through the ISO. The ISO-versus-direct guide on this blog weighs that against applying to one acquirer yourself.
IBOCore is processor-agnostic. You bring any ISO you already trust or apply directly; IBOCore stays out of the application. The optional merchant account consulting add-on ($899 per month) adds one-on-one guidance on which acquirer to approach and how to structure the application.
The PayFac: the aggregator that boards you under its own MID
A payment facilitator, or PayFac, is registered with the card networks and holds a master MID at a sponsor acquirer. Instead of sending you to that acquirer, it boards you as a sub-merchant under its own account: it underwrites you itself, often by automation, carries your risk toward its acquirer, receives your settlements and pays you out on its own schedule. You do not get a MID of your own. The model suits small, low-risk, domestically run businesses and tends to close on the profiles an acquirer would have declined up front: high-risk verticals, foreign-run entities, fast volume growth, rising disputes. Its risk rules then close the sub-merchant account and hold the balance, and there is no acquirer to escalate to; the relationship was never yours. The aggregator closure guide on this blog covers what to do at that point. The structural answer is a dedicated MID at an acquirer, underwritten on your own entity and signer, which is what an IBO package is built for.
Who decides what: approval, reserve, holds and termination
The same questions come up at every stage. This is who owns each one and who you hear it from.
| Question | Who decides | Who tells you |
|---|---|---|
| Is the application approved? | The acquirer's underwriting team | Your ISO, or the acquirer if you applied direct |
| How large is the reserve and when is it released? | The acquirer, per the merchant agreement | The acquirer, usually through the ISO |
| Why is a settlement late or held? | The acquirer's risk team | The acquirer, usually through the ISO |
| Why does every card decline at checkout? | No one, unless the acquirer suspended the MID; otherwise a gateway or processor fault | Gateway support first, then the processor through your ISO; the acquirer if it suspended the MID |
| Why was the MID terminated? | The acquirer | The acquirer in writing; the ISO relays it and cannot reverse it |
| Why was the sub-merchant account closed? | The PayFac | The PayFac; you have no acquirer contact |
Who to call when something breaks
- Every card fails with the same technical code: the gateway, first. Check credentials and status, then have the ISO open a ticket with the processor.
- One card declines, others work: the issuing bank said no. The processor can show the response code; nobody in the chain overrides an issuer decline.
- Settlement late, short or missing: the acquirer, through your ISO. Ask whether the risk team placed a hold and which document clears it.
- Reserve release or cap increase: the acquirer, per the merchant agreement. The ISO carries the request and the processing history behind it.
- Termination notice: the acquirer's risk team, in writing. Ask for the reason, the reserve release schedule and whether it was reported to MATCH.
- Sub-merchant account closed at a PayFac: the PayFac alone. Get the payout schedule in writing and start the application for a dedicated MID.
IBOCore is missing from that list on purpose: it is none of the five. It does not underwrite, does not move money and does not run the checkout. It supplies what the acquirer's file needs from your side. The entity: a US LLC or C-Corp incorporated in the director's home state, with its EIN. The director: a nominee director, the Independent Business Operator (IBO), a real, KYC-verified US resident with zero criminal record and a credit score of 650 or more. The bank account: at Bluebanc or Relay, in the company's name, with full operational access. Plus the complete director and business documentation, an email on the company domain and a dedicated US residential proxy. Requests that need the director, such as the verification call or a signature on a pend, go through your private Telegram group with your account manager. The business itself, the description, the site and the projections, stays with you.
One entity, one director, any acquirer
Packages ship the same day payment confirms. Bring your own ISO or apply directly; there is no clawback on IBOCore's side if an acquirer terminates a MID.
Questions merchants ask
Is the acquirer the same company as the processor?
Sometimes. Some acquirers run their own processing platform; others license a third-party processor that serves many acquirers. The name on your merchant agreement is the acquirer of record, the party that underwrites you, holds your reserve and can terminate the MID; the processor's name may only appear on batch reports. If a contract does not say which bank is the acquirer of record, ask before signing.
Does the ISO decide whether my application is approved?
No. The ISO pre-screens the file against the acquirers it is registered with and submits it to the one it expects will board you; the acquirer's underwriting team decides. An ISO that knows each acquirer's appetite sends the file where it fits and gets pends answered quickly; a careless one sends it to an acquirer that never boards your vertical. Neither changes who signs the approval.
Do I need all five parties to accept cards?
No. The minimum for a dedicated merchant account is an acquirer, the processor it runs on and a gateway; some acquirers take applications directly, which skips the ISO, though many merchants use one to reach several acquirers, and some acquirers only board through ISOs. A PayFac collapses the chain into one sign-up, which is convenient until its risk rules close the account. What an IBO package adds is not a sixth party but the applicant: the entity, the director who signs and answers the call, and the bank account the acquirer settles to. Delivery is the same day payment confirms; acquirer onboarding then typically takes 3 to 10 business days, on the acquirer's timeline.
High-risk MID metrics acquirers watch
Once live, your chargeback ratio (CB ratio) is chargebacks divided by transactions; Visa VDMP and Mastercard ECP programs trigger when you breach network thresholds. Rolling reserves (often 10% for 180 days) protect the acquirer against future disputes. MATCH (Terminated Merchant File) is the industry blacklist after a forced termination. MCC (Merchant Category Code) must reflect your real vertical; miscoding is a scheme violation.
- Representment: fighting a chargeback with delivery proof and logs.
- RDR / Ethoca alerts: pre-chargeback refund tools that protect your CB ratio.
- Statement descriptor: keep it recognizable to cut "friendly fraud" disputes.
- Processing cap: volume limit until the acquirer trusts your history.
MID stacking without structure
Spreading volume across many MIDs without separate entities looks like ratio gaming or transaction laundering to risk teams. The durable pattern is one IBO package per MID, clean descriptors, honest MCC, and reserves treated as a cost of doing high-risk volume.
FAQ: quick answers
How fast can I get an IBO package on IBOCore?
Available inventory ships the same day after payment. You receive Articles, EIN letter, registered agent details, bank onboarding pack and signer contact through your merchant dashboard. Processor onboarding typically follows over the next one to two weeks.
Where can I look up payment-processing jargon?
Use the Resources glossary on IBOCore (/resources) for 580+ definitions: MID, chargeback ratio, MATCH, rolling reserve, MCC, RDR, KYB and high-risk vertical vocabulary.
Ready for instant delivery?
Browse live IBO inventory or ask about your vertical on Telegram.
