BIN lookup · Mastercard · EEA (Europe) · log through 13 Sep 2026 14:40 UTC

521539 Virtual Card Review - EEA (Europe) Mastercard Debit

Bottom line

Tested across 6 weeks. Steam, Google Play, App Store held at or above 127 passes, and the failures clustered on two merchants only.

521539Mastercard EEA (Europe)Debit 127/181 cleared

Short entry for a range that punches above its weight. 521539 comes from Blackcatcard, EEA (Europe), Mastercard, Debit. It is the card we hand people who have already failed twice elsewhere.

What 521539 actually is

BIN
521539
Card network
Mastercard
Issuing country
EEA (Europe)
Card type
Debit
Issued by
Blackcatcard
Card form
Virtual only
KYC tier
ID + proof
3-D Secure
Yes
AVS check
No
Billing address
EU IBAN
Funding methods
Crypto · Bank transfer
Max cards per account
Unlimited
Issuer risk rating
Low-Medium

Costs, stacked up

The money side is simple: no issuance fee, no top-up fee, and no FX markup on anything billed outside USD. Nobody advertises the decline fee, so we list it. That is the number that surprises people.

Card creation feeFree
Monthly feeFree (1 card); €2/mo (2+ cards)
Top-up fee
FX / conversion fee
Declined transaction fee
Minimum top-up

Cleared versus declined

Attempts counted per merchant by hand from the log, so a single declined order does not skew the rate.

Merchant by merchant

MerchantAttemptsClearedRateWhat happened
Steam575189%cleared, 3-D Secure completed in-app in under 20 seconds
Google Play474085%cleared, 3-D Secure completed in-app in under 20 seconds
App Store363083%cleared on the first attempt, no challenge issued
Walmart2300%Soft decline on the retry after an earlier failure on the same account.
Sephora US18633%Geo mismatch. The connection country did not match the card's country of issue.

Run from a EEA (Europe)-region account between 21 Jul to 01 Sep 2026, with the billing address set to the issuer default unless noted. Declines were logged with the reason the gateway returned.

Failures we could not fix

Walmart rejected it outright. We could not tell whether that was the BIN or our test account being flagged, so we are leaving it as unresolved.

What to change before you retry

Three things worth doing

  1. Card issuance is effectively unlimited here. Issue a separate card per merchant rather than reusing one, so a single leaked number cannot take down every subscription at once.
  2. Paste the EEA (Europe) billing address Blackcatcard generates rather than typing your own. One transposed digit is enough to fail the check.
  3. Bank transfer is the cheap funding route here, but it is not instant. Top up a day before a renewal rather than the same morning.

Worth it?

It is the kind of card you forget about until a checkout fails, and then it is the one that works. Worth keeping if your merchants sit in EEA (Europe). Worth ignoring if they do not.

FAQ

What does the 521539 BIN tell a merchant?

In practice the checkout reads Blackcatcard / EEA (Europe) / Debit and decides. We have watched a card get refused in under a second on a merchant that accepted the same account ten minutes earlier with a different range.

Is 521539 a real card number?

No, and this trips people up. 521539 is a range identifier shared across every card Blackcatcard issues in EEA (Europe). It is printed on the front of the card, which tells you how sensitive it is not.

Why would 521539 be declined if the range is fine?

Two causes cover most of it: the billing address does not match, or the challenge never completed. Both look identical on screen, and both are fixable in under a minute.

Can thousands of people share the same BIN?

That is the normal case. Every Debit card Blackcatcard issues in EEA (Europe) carries the same six digits. Two people on 521539 can get opposite results at the same checkout, which is why a single review is never conclusive.

How this test was run

We bought a Blackcatcard card, funded it, and pushed 181 charges through live merchant checkout pages between 21 Jul to 01 Sep 2026. Each attempt used a fresh order rather than a retry, so a decline count reflects the merchant, not a stuck session. 127 cleared.

Counting rules

Renewals count alongside first charges, which is why a range that passed once and failed a month later reads lower here than on a first-charge-only list. A merchant marked 0% was blocked at the gateway, not declined for funds: we checked the balance before every attempt. Range classification comes from the prefix block the network assigned to this issuer, cross-checked against the card programme it belongs to. Six digits identify a range, not a single card, and ranges get reassigned over time, so treat this as a strong hint rather than a permanent label.

Log through 13 Sep 2026 14:40 UTC · rate last re-checked 07 September 2026 · 181 charges on record for this range.