diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index d1692e2ac..8d2bdd1ba 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -314,6 +314,14 @@ uint32_t iso14a_get_timeout(void) {
     return iso14a_timeout - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER) / 128 - 2;
 }
 
+void iso14a_rebase_transfer_time(void) {
+    // NextTransferTime is expressed in absolute SSP-clock counts. A caller
+    // that restarts StartCountSspClk() resets that counter to zero; retaining
+    // the old value would make ReaderTransmit() wait for stale time from the
+    // preceding APDU. Do not reset PCB or ATS state here.
+    NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
+}
+
 //-----------------------------------------------------------------------------
 // Generate the parity value for a byte sequence
 //-----------------------------------------------------------------------------
diff --git a/armsrc/iso14443a.h b/armsrc/iso14443a.h
index 1f39be439..575a23184 100644
--- a/armsrc/iso14443a.h
+++ b/armsrc/iso14443a.h
@@ -129,6 +129,9 @@ void setHf14aConfig(const hf14a_config_t *hc);
 hf14a_config_t *getHf14aConfig(void);
 void iso14a_set_timeout(uint32_t timeout);
 uint32_t iso14a_get_timeout(void);
+// Rebase the absolute reader-transfer schedule after a caller restarts the
+// SSP clock counter. This preserves the active ISO14443-4 session.
+void iso14a_rebase_transfer_time(void);
 
 void GetParity(const uint8_t *pbtCmd, uint16_t len, uint8_t *par);
 
diff --git a/armsrc/sam_sc.c b/armsrc/sam_sc.c
index 5bcd88395..cf7e7b73c 100644
--- a/armsrc/sam_sc.c
+++ b/armsrc/sam_sc.c
@@ -366,6 +366,12 @@ static int sam_sc_card_api_loop(uint8_t *response, uint16_t *response_len,
                 }
                 if (iso14a) {
                     switch_clock_to_countsspclk();
+                    // This counter is reset for the RF exchange so the SAM
+                    // path can return to millisecond ticks afterwards. Keep
+                    // ISO14443A's absolute transfer scheduler in the same
+                    // time base; otherwise it waits on a stale timestamp
+                    // from the preceding Card-API APDU.
+                    iso14a_rebase_transfer_time();
                     int apdu_len = iso14_apdu((uint8_t *)op_value, op_len, false,
                                               nfc_rx, sizeof(nfc_rx), NULL);
                     switch_clock_to_ticks();