diff --git a/src_features/provideTxSimu/cmd_getTxSimulation.c b/src_features/provideTxSimu/cmd_getTxSimulation.c
index 8fe8b43830..97200d3166 100644
--- a/src_features/provideTxSimu/cmd_getTxSimulation.c
+++ b/src_features/provideTxSimu/cmd_getTxSimulation.c
@@ -43,6 +43,19 @@ enum {
     TAG_DER_SIGNATURE = 0x15,
 };
 
+// This enum needs to be ordered the same way as the TAGGs above !
+enum {
+    BIT_STRUCTURE_TYPE,
+    BIT_STRUCTURE_VERSION,
+    BIT_CHAIN_ID,
+    BIT_TX_HASH,
+    BIT_W3C_NORMALIZED_RISK,
+    BIT_W3C_NORMALIZED_CATEGORY,
+    BIT_W3C_PROVIDER_MSG,
+    BIT_W3C_TINY_URL,
+    BIT_DER_SIGNATURE,
+};
+
 // clang-format off
 static const char *const TX_SIMULATION_CATEGORY[CATEGORY_NB_MAX] = {
     "Raw signing detected",   // CATEGORY_RAW_SIGNING
@@ -305,6 +318,28 @@ static bool verify_signature(s_sig_ctx *sig_ctx) {
     return ret_code;
 }
 
+/**
+ * @brief Verify the received fields
+ *
+ * Check the mandatory fields are present
+ *
+ * @param[in] rcv_bit indicates received fields
+ * @return whether it was successful
+ */
+static bool verify_fields(uint32_t rcv_bit) {
+    uint32_t expected_fields;
+    expected_fields = (1 << BIT_STRUCTURE_TYPE) | (1 << BIT_STRUCTURE_VERSION) |
+                      (1 << BIT_CHAIN_ID) | (1 << BIT_TX_HASH) | (1 << BIT_W3C_NORMALIZED_RISK) |
+                      (1 << BIT_W3C_NORMALIZED_CATEGORY) | (1 << BIT_W3C_TINY_URL) |
+                      (1 << BIT_DER_SIGNATURE);
+
+    if ((rcv_bit & expected_fields) != expected_fields) {
+        return false;
+    }
+
+    return true;
+}
+
 /**
  * @brief Print the simulation parameters.
  *
@@ -384,6 +419,7 @@ static uint16_t parse_tlv(const uint8_t *data, uint8_t length) {
     uint16_t sw = APDU_RESPONSE_INTERNAL_ERROR;
     uint32_t tag_start_off;
     s_sig_ctx sig_ctx = {0};
+    uint32_t rcv_bit = 0;
 
     // Reset the structures
     explicit_bzero(&TX_SIMULATION, sizeof(tx_simulation_t));
@@ -408,30 +444,39 @@ static uint16_t parse_tlv(const uint8_t *data, uint8_t length) {
         switch (field_tag) {
             case TAG_STRUCTURE_TYPE:
                 sw = parse_struct_type(data + offset, field_len);
+                rcv_bit |= (1 << BIT_STRUCTURE_TYPE);
                 break;
             case TAG_STRUCTURE_VERSION:
                 sw = parse_struct_version(data + offset, field_len);
+                rcv_bit |= (1 << BIT_STRUCTURE_VERSION);
                 break;
             case TAG_CHAIN_ID:
                 sw = parse_chain_id(data + offset, field_len);
+                rcv_bit |= (1 << BIT_CHAIN_ID);
                 break;
             case TAG_TX_HASH:
                 sw = parse_tx_hash(data + offset, field_len);
+                rcv_bit |= (1 << BIT_TX_HASH);
                 break;
             case TAG_W3C_NORMALIZED_RISK:
                 sw = parse_risk(data + offset, field_len);
+                rcv_bit |= (1 << BIT_W3C_NORMALIZED_RISK);
                 break;
             case TAG_W3C_NORMALIZED_CATEGORY:
                 sw = parse_category(data + offset, field_len);
+                rcv_bit |= (1 << BIT_W3C_NORMALIZED_CATEGORY);
                 break;
             case TAG_W3C_PROVIDER_MSG:
                 sw = parse_provider_msg(data + offset, field_len);
+                rcv_bit |= (1 << BIT_W3C_PROVIDER_MSG);
                 break;
             case TAG_W3C_TINY_URL:
                 sw = parse_tiny_url(data + offset, field_len);
+                rcv_bit |= (1 << BIT_W3C_TINY_URL);
                 break;
             case TAG_DER_SIGNATURE:
                 sw = parse_signature(data + offset, field_len, &sig_ctx);
+                rcv_bit |= (1 << BIT_DER_SIGNATURE);
                 break;
             default:
                 PRINTF("Skipping unknown tag: %d\n", field_tag);
@@ -449,7 +494,10 @@ static uint16_t parse_tlv(const uint8_t *data, uint8_t length) {
         }
     }
     if (sw == APDU_RESPONSE_OK) {
-        if (verify_signature(&sig_ctx) == false) {
+        if (verify_fields(rcv_bit) == false) {
+            PRINTF("Missing fields!\n");
+            sw = APDU_RESPONSE_INVALID_DATA;
+        } else if (verify_signature(&sig_ctx) == false) {
             PRINTF("Signature verification failed!\n");
             sw = APDU_RESPONSE_INVALID_DATA;
         }