diff --git a/openapi.json b/openapi.json
index 84e5369..cc9d802 100644
--- a/openapi.json
+++ b/openapi.json
@@ -2531,7 +2531,7 @@
             ],
             "get": {
                 "summary": "List account balances",
-                "description": "Returns the latest balances for the accounts granted by the consent. For one-off consents balances are reported as of authorization time; for recurring consents they reflect the retrieval time.",
+                "description": "Returns the latest balances for the accounts granted by the consent. Each item contains fixed metadata plus dynamic numeric fields keyed by normalized bank balance type. For one-off consents balances are reported as of authorization time; for recurring consents they reflect the retrieval time.",
                 "operationId": "listAisConsentBalances",
                 "tags": [
                     "AIS"
@@ -2592,7 +2592,7 @@
                         "name": "accountId",
                         "in": "query",
                         "required": false,
-                        "description": "Filter by account identifier when the consent covers multiple accounts.",
+                        "description": "Legacy account filter. Pass the IBAN of the account to scope the transaction list.",
                         "schema": {
                             "type": "string"
                         }
@@ -4210,10 +4210,6 @@
             "AisAccount": {
                 "type": "object",
                 "properties": {
-                    "accountId": {
-                        "type": "string",
-                        "description": "Identifier of the account as provided by the ASPSP."
-                    },
                     "iban": {
                         "type": "string",
                         "description": "IBAN when available."
@@ -4226,10 +4222,46 @@
                         "type": "string",
                         "description": "ISO 4217 currency code.",
                         "example": "EUR"
+                    },
+                    "closingBooked": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "interimBooked": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "openingBooked": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "interimAvailable": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "forwardAvailable": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "creditLimit": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "expected": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "available": {
+                        "type": "number",
+                        "format": "double"
+                    },
+                    "booked": {
+                        "type": "number",
+                        "format": "double"
                     }
                 },
                 "required": [
-                    "accountId",
+                    "iban",
                     "currency"
                 ]
             },
@@ -4261,35 +4293,49 @@
             },
             "AisBalance": {
                 "type": "object",
+                "description": "AIS balance payload. Fixed metadata fields are always present; numeric balance fields depend on what the bank exposes and may vary by provider.",
                 "properties": {
-                    "accountId": {
+                    "iban": {
                         "type": "string"
                     },
-                    "asOf": {
+                    "date": {
                         "type": "string",
                         "format": "date-time"
                     },
-                    "current": {
+                    "currency": {
+                        "type": "string",
+                        "description": "ISO 4217 currency code.",
+                        "example": "EUR"
+                    },
+                    "closingBooked": {
                         "type": "number",
                         "format": "double"
                     },
-                    "available": {
+                    "interimAvailable": {
                         "type": "number",
                         "format": "double"
                     },
-                    "creditLimit": {
+                    "expected": {
                         "type": "number",
                         "format": "double"
-                    },
-                    "currency": {
-                        "type": "string",
-                        "description": "ISO 4217 currency code.",
-                        "example": "EUR"
                     }
                 },
+                "additionalProperties": {
+                    "type": "number",
+                    "format": "double",
+                    "description": "Balance amount keyed by normalized bank balance type (for example closingBooked or interimAvailable)."
+                },
+                "example": {
+                    "iban": "IT60X0542811101000000123456",
+                    "date": "2026-03-12T14:15:22Z",
+                    "currency": "EUR",
+                    "closingBooked": 5174.72,
+                    "interimAvailable": 5200,
+                    "expected": -262.01
+                },
                 "required": [
-                    "accountId",
-                    "asOf",
+                    "iban",
+                    "date",
                     "currency"
                 ]
             },
@@ -4353,7 +4399,7 @@
                         "type": "string",
                         "description": "Stable identifier of the transaction."
                     },
-                    "accountId": {
+                    "iban": {
                         "type": "string"
                     },
                     "bookingDate": {
@@ -4384,7 +4430,7 @@
                 },
                 "required": [
                     "transactionId",
-                    "accountId",
+                    "iban",
                     "bookingDate",
                     "amount",
                     "currency"
@@ -4422,4 +4468,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}