diff --git a/src/fido/cbor_get_assertion.c b/src/fido/cbor_get_assertion.c
index 5514c6e..7619884 100644
--- a/src/fido/cbor_get_assertion.c
+++ b/src/fido/cbor_get_assertion.c
@@ -193,6 +193,7 @@ int cbor_get_assertion(const uint8_t *data, size_t len, bool next) {
                 }
                 CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "credBlob", credBlob);
                 CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "largeBlobKey", extensions.largeBlobKey);
+                CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "thirdPartyPayment", extensions.thirdPartyPayment);
                 CBOR_ADVANCE(2);
             }
             CBOR_PARSE_MAP_END(_f1, 2);
@@ -460,6 +461,9 @@ int cbor_get_assertion(const uint8_t *data, size_t len, bool next) {
         if (credBlob == ptrue) {
             l++;
         }
+        if (extensions.thirdPartyPayment != NULL) {
+            l++;
+        }
         CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, l));
         if (credBlob == ptrue) {
             CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "credBlob"));
@@ -538,6 +542,15 @@ int cbor_get_assertion(const uint8_t *data, size_t len, bool next) {
             encrypt(hmacSecretPinUvAuthProtocol, sharedSecret, out1, salt_enc.len - poff, hmac_res);
             CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, hmac_res, salt_enc.len));
         }
+        if (extensions.thirdPartyPayment != NULL) {
+            CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "thirdPartyPayment"));
+            if (selcred->extensions.thirdPartyPayment == ptrue) {
+                CBOR_CHECK(cbor_encode_boolean(&mapEncoder, true));
+            }
+            else {
+                CBOR_CHECK(cbor_encode_boolean(&mapEncoder, false));
+            }
+        }
 
         CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
         ext_len = cbor_encoder_get_buffer_size(&encoder, ext);
diff --git a/src/fido/cbor_make_credential.c b/src/fido/cbor_make_credential.c
index 4ffc8bd..987f768 100644
--- a/src/fido/cbor_make_credential.c
+++ b/src/fido/cbor_make_credential.c
@@ -124,6 +124,7 @@ int cbor_make_credential(const uint8_t *data, size_t len) {
                 CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "minPinLength", extensions.minPinLength);
                 CBOR_FIELD_KEY_TEXT_VAL_BYTES(2, "credBlob", extensions.credBlob);
                 CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "largeBlobKey", extensions.largeBlobKey);
+                CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "thirdPartyPayment", extensions.thirdPartyPayment);
                 CBOR_ADVANCE(2);
             }
             CBOR_PARSE_MAP_END(_f1, 2);
diff --git a/src/fido/credential.c b/src/fido/credential.c
index bae5fb5..aba002c 100644
--- a/src/fido/credential.c
+++ b/src/fido/credential.c
@@ -98,6 +98,10 @@ int credential_create(CborCharString *rpId,
             CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "largeBlobKey"));
             CBOR_CHECK(cbor_encode_boolean(&mapEncoder2, true));
         }
+        if (extensions->thirdPartyPayment == ptrue) {
+            CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "thirdPartyPayment"));
+            CBOR_CHECK(cbor_encode_boolean(&mapEncoder2, true));
+        }
         CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &mapEncoder2));
     }
     CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x08));
@@ -201,6 +205,7 @@ int credential_load(const uint8_t *cred_id,
                     CBOR_FIELD_KEY_TEXT_VAL_UINT(2, "credProtect", cred->extensions.credProtect);
                     CBOR_FIELD_KEY_TEXT_VAL_BYTES(2, "credBlob", cred->extensions.credBlob);
                     CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "largeBlobKey", cred->extensions.largeBlobKey);
+                    CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "thirdPartyPayment", cred->extensions.thirdPartyPayment);
                     CBOR_ADVANCE(2);
                 }
                 CBOR_PARSE_MAP_END(_f1, 2);
diff --git a/src/fido/credential.h b/src/fido/credential.h
index f883050..313077b 100644
--- a/src/fido/credential.h
+++ b/src/fido/credential.h
@@ -33,6 +33,7 @@ typedef struct CredExtensions {
     const bool *minPinLength;
     CborByteString credBlob;
     const bool *largeBlobKey;
+    const bool *thirdPartyPayment;
     bool present;
 } CredExtensions;