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What counts as VAMP enumeration

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Enumeration is Visa’s card-testing metric under VAMP. It is not the dispute ratio that uses TC40 fraud and TC15 disputes over settled sales. Mixing them is how you “fix” the wrong line.

Pair: VAMP enumeration ratio on Chargebacks. Dispute ratio stays on rate vs threshold.

What Visa’s public formula counts

From Visa’s VAMP fact sheet: enumerated authorization transactions (approved + declined) ÷ authorization transactions (approved + declined).

Numerator. Auths Visa identifies as enumeration (card testing). Approved and declined both sit in. Type the count from the acquirer or Visa extract — not a gateway decline total you invented.

Denominator. All authorization attempts in the same window, approved and declined. Not settled sales (TC05). Not CRM paid. Attempts that never settle still sit here.

Visa also names a count floor: enumerated transactions ≥ 300,000 in the month, paired with a ratio ≥ 2,000 bps (20%). Both conditions matter for exceeding the public enumeration thresholds. Confirm current figures on the Visa fact sheet your acquirer cites.

What this is not

Not primary chargebacks ÷ approved sales. Not RDR mix. Not “we declined the bots so we are fine.” Declines still count in the auth denominator and, when Visa flags them, in the numerator.

What not to do

Do not use settled sales as the denominator. Do not treat gateway “suspicious” tags as Visa’s enumerated count. Do not ignore volume because the dispute ratio looks calm.

Related: Chargebacks, rate vs threshold, MIDs.

Procedure

  1. Pull Visa-identified enumerated auth count for the month.
  2. Pull all auth attempts (approved + declined) for the same window.
  3. Read the ratio against the public 20% / 300,000 paired lines.
  4. Stop card-testing exposure before you argue the dispute ratio.

Failure modes

  • Using settled sales as the denominator.
  • Guessing enumerated count from gateway declines.
  • Treating the dispute VAMP ratio as the enumeration line.

Worked example

None on this page yet. When one lands it will be a real case: what broke, the number, and what changed. Not a composite.

Glossary

Enumeration
Visa-identified card-testing authorization attempts. Approved and declined both count. Not the dispute VAMP ratio.

Work with us — We run this job on your accounts. Services

FAQ

Is enumeration the same as my chargeback ratio?
No. Enumeration is Visa-flagged card-testing auths over all auth attempts. The dispute VAMP ratio uses fraud and disputes over settled sales.
Do declined card tests count?
Yes. Visa’s public formula counts enumerated authorizations approved and declined. Blocking after auth does not erase the attempt.
Can I guess the enumerated count from my gateway declines?
No. Type the Visa-identified count from the acquirer or Visa report. Your decline pile is not the numerator.