All Mercado Pago codes
MERCADO PAGO · STATUS_DETAIL

Mercado Pago
cc_rejected_duplicated_payment

A payment for the same value was already made; to pay again use a different card or payment method.

Mercado Pago saysIntegration issue
cc_rejected_duplicated_payment

A payment for the same value was already made; to pay again use a different card or payment method.

What it means

Duplicate transaction

An identical payment was sent very recently, so this one was blocked.

What to do

Confirm whether the first one succeeded before sending again, and use unique order references.

Don't retry as-isWho can fix it: You, the merchant
Yuno response codeDUPLICATED_TRANSACTION
Source:Mercado Pago docs — Checkout API (Payments): Get payment status

Reference only. Codes and descriptions come from each provider's public documentation. The Yuno response code is a reference mapping and does not guarantee how a specific transaction is processed.