https://community.squareup.com/t5/Payments-Troubleshooting/Mastercard-not-working-via-Square-Reader/m-p/714069#M40538 <P>We are seeing most (but not all) Mastercard transactions fail via the square reader (red light and failed message in POS)&nbsp;</P><P>&nbsp;</P><P>The same card works fine by tapping directly on a seperate iPhone logged in with same account.</P><P>&nbsp;</P><P>Have raised a support issue but so far they dont have any answers</P> Sun, 21 Sep 2025 07:20:22 GMT edsawkins 2025-09-21T07:20:22Z https://community.squareup.com/t5/Payments-Troubleshooting/Mastercard-not-working-via-Square-Reader/m-p/714069#M40538 <P>We are seeing most (but not all) Mastercard transactions fail via the square reader (red light and failed message in POS)&nbsp;</P><P>&nbsp;</P><P>The same card works fine by tapping directly on a seperate iPhone logged in with same account.</P><P>&nbsp;</P><P>Have raised a support issue but so far they dont have any answers</P> Sun, 21 Sep 2025 07:20:22 GMT https://community.squareup.com/t5/Payments-Troubleshooting/Mastercard-not-working-via-Square-Reader/m-p/714069#M40538 edsawkins 2025-09-21T07:20:22Z