What is Know Your Business?
Also: KYB
Onboarding due diligence on a legal entity: incorporation, licences, UBOs, sanctions, and business model, mandated for acquirers under AML rules.
Know Your Business (KYB) is the due diligence process undertaken by an acquirer to verify the identity and legitimacy of a legal entity seeking to accept card payments.
This involves the collection and assessment of documentation such as company registration certificates, business licences, and details of ultimate beneficial owners (UBOs) and directors to comply with anti-money laundering (AML) and counter-terrorist financing (CTF) regulations.
The acquirer performs checks against sanctions lists, politically exposed persons (PEP) databases, and adverse media to identify any potential risks associated with the applicant business.
For a merchant, KYB is typically encountered during the application phase for a merchant account, where they must provide extensive corporate information and supporting documents to their prospective acquirer.
Delays in the KYB process can impact the onboarding timeline, preventing a merchant from accepting card payments until all checks are satisfactorily completed and approved.
A common issue arises when a business undergoes a change in ownership or control (e. g. , a change in UBOs or a merger), as this often triggers a requirement for re-KYB by the acquirer to ensure ongoing compliance with regulatory obligations.
Worked example
A merchant reviews a £650 transaction where Know Your Business is the deciding factor. The merchant scores the order, checks card and customer signals, applies a manual review threshold, and either releases, rejects, or routes the transaction with stronger controls.
The operational cost is modelled at 25 basis points of expected fraud loss, or £1.63, and the relevant action must complete before capture. Step 1 is to capture the original request data, including amount, currency, issuer country, MID, and response or status code.
Step 2 is to apply the merchant's rule set, for example whether to retry, challenge, refund, release goods, or hold for review. Step 3 is to reconcile the result against acquirer reporting so finance can see the cash impact.
If the rule improves the outcome by even 50 basis points on 2,000 similar monthly transactions, the merchant protects roughly 10 extra orders from avoidable failure or loss.
Scheme notes
Visa, Mastercard, American Express, and Discover all monitor merchant risk, but programme names, thresholds, and escalation paths differ. Visa uses VAMP and integrity programmes for excessive disputes, fraud, and prohibited activity, while Mastercard uses programmes such as ECP, BRAM, SAFE reporting, and MATCH.
Acquirers may apply stricter controls than the schemes, including rolling reserves, delayed settlement, or termination, because they carry portfolio-level liability.
Why it matters for merchants
Commercially, this affects fraud losses, reserve requirements, scheme monitoring exposure, and whether a merchant can keep processing at scale.
For a merchant processing £500,000 per month, a 25 basis point movement is worth £1,250 before secondary effects such as disputes, reserves, support tickets, or failed delivery costs.
The impact is larger in high-risk, subscription, travel, digital-goods, and cross-border models because issuer decisions and scheme monitoring can compound quickly.
Cardflo can help by combining acquiring access, MID routing, orchestration rules, KYB review, and chargeback tooling where relevant, so the merchant is not dependent on one processor interpretation or one fixed transaction path.
Frequently asked
Which data should a merchant store for Know Your Business?
Store the transaction ID, MID, acquirer, amount, currency, issuer country, card scheme, response or status code, timestamp, and any 3DS, exemption, refund, or dispute reference. For card transactions, keep authorisation and Clearing identifiers because settlement or chargeback questions may arrive 30 to 120 days later.
For regulated flows, keep customer consent and evidence records for at least the period required by local law or scheme rules. Good records reduce investigation time from hours to minutes when acquirer reporting does not match the order system.
How often should Know Your Business be reviewed?
High-volume merchants should review exception rates weekly and trend the main metric monthly by scheme, acquirer, issuer country, MCC, and payment method. A movement of 20 to 50 basis points can be material if the merchant processes thousands of orders.
Finance should reconcile the cash impact at settlement level, while risk or payment operations should analyse the root cause. Reviewing only blended totals hides problems that appear on a single BIN range, region, or MID.
What threshold usually triggers action on Know Your Business?
The threshold depends on the category, but merchants should investigate any sudden change above 10% relative movement or 25 basis points absolute movement. For disputes and fraud, scheme thresholds such as 0.9% under Visa monitoring or 1.5% under Mastercard ECM can create immediate escalation risk.
For settlement or pricing items, even 5 to 15 basis points can justify routing or contract review. The key is to set thresholds before month-end, not after a processor invoice or scheme notice arrives.
Can Know Your Business differ between acquirers?
Yes. Acquirers can map response codes differently, apply different risk rules, support different data fields, and settle on different cycles.
One acquirer may return a generic decline while another exposes issuer advice that allows a safe retry. Fee treatment can also vary by contract, especially for cross-border, FX, premium cards, and alternative payment methods.
This is why merchants using orchestration should compare performance by acquirer and scheme rather than relying on a single blended approval or cost figure.
What is the first remediation step when Know Your Business creates losses?
Start with a 30-day sample and split it by scheme, issuer country, card product, payment method, MID, and response or dispute code. Quantify the value at risk in cash terms, not just percentage points.
Then decide whether the fix is operational, such as better evidence or customer communication, technical, such as richer data or 3DS indicators, or commercial, such as a different acquirer route.
Recheck the same metric after one full settlement or dispute cycle to confirm the change worked.
See how Know Your Business plays out in practice
Industries and regions where this term drives real acquiring, routing, or dispute decisions.
Related terms
Regulated identity-verification of the merchant (KYB) and, where relevant, the merchant's customers (KYC).
Natural person(s) owning or controlling 25%+ of a legal entity, whose identity acquirers must verify and screen during KYB.
The regulatory regime that obligates payment institutions to detect and report suspicious activity.
Screening customers, UBOs, and counterparties against OFAC, UN, EU, and HM Treasury sanction lists during onboarding and ongoing monitoring.
Related guides.
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