diff --git a/l10n_br_cte/models/aereo.py b/l10n_br_cte/models/aereo.py
index 628a2c353068..9c3ad9069396 100644
--- a/l10n_br_cte/models/aereo.py
+++ b/l10n_br_cte/models/aereo.py
@@ -18,9 +18,7 @@ class Aereo(spec_models.SpecModel):
         store="True",
     )
 
-    cte40_natCarga = fields.One2many(
-        related="document_id.fiscal_line_ids",
-    )
+    cte40_natCarga = fields.Many2one(comodel_name="l10n_br_cte.modal.aereo.natcarga")
 
     cte40_tarifa = fields.Many2one(comodel_name="l10n_br_cte.modal.aereo.tarifa")
 
@@ -54,3 +52,32 @@ def export_fields(self):
     @api.model
     def export_fields_multi(self):
         return [record.export_fields() for record in self]
+
+
+class NatCarga(spec_models.SpecModel):
+    _name = "l10n_br_cte.modal.aereo.natcarga"
+    _inherit = "cte.40.tarifa"
+
+    document_id = fields.Many2one(comodel_name="l10n_br_fiscal.document")
+
+    cte40_xDime = fields.Char(
+        string="Dimensão",
+        help=(
+            "Dimensão\nFormato:1234X1234X1234 (cm). Esse campo deve sempre que"
+            " possível ser preenchido. Entretanto, quando for impossível o "
+            "preenchimento das dimensões, fica obrigatório o preenchimento da "
+            "cubagem em metro cúbico do leiaute do CT-e da estrutura genérica "
+            "(infQ)."
+        ),
+    )
+
+    @api.model
+    def export_fields(self):
+        if len(self) > 1:
+            return self.export_fields_multi()
+
+        return Aquav.Tarifa(xDime=self.cte40_xDime)
+
+    @api.model
+    def export_fields_multi(self):
+        return [record.export_fields() for record in self]
diff --git a/l10n_br_cte/models/aquaviario.py b/l10n_br_cte/models/aquaviario.py
index f6d29620c19b..84308821f036 100644
--- a/l10n_br_cte/models/aquaviario.py
+++ b/l10n_br_cte/models/aquaviario.py
@@ -10,10 +10,6 @@ class Aquaviario(spec_models.SpecModel):
     _name = "l10n_br_cte.modal.aquaviario"
     _inherit = "cte.40.aquav"
 
-    document_id = fields.One2many(
-        comodel_name="l10n_br_fiscal.document", inverse_name="cte40_aquav"
-    )
-
     cte40_vPrest = fields.Monetary(compute="_compute_vPrest", store=True)
 
     cte40_vAFRMM = fields.Monetary(
diff --git a/l10n_br_cte/models/document.py b/l10n_br_cte/models/document.py
index e135dd360736..c744eef2e9c9 100644
--- a/l10n_br_cte/models/document.py
+++ b/l10n_br_cte/models/document.py
@@ -483,7 +483,7 @@ def _default_cte40_autxml(self):
     )
 
     cte40_natCarga = fields.One2many(
-        related="document_id.fiscal_line_ids",
+        related="fiscal_line_ids",
     )
 
     cte40_tarifa = fields.Many2one(comodel_name="l10n_br_cte.tarifa")
@@ -534,8 +534,10 @@ def _default_cte40_autxml(self):
     )
 
     def _compute_vPrest(self):
-        for record in self.document_id.fiscal_line_ids:
-            record.cte40_vPrest += record.cte40_vTPrest
+        vPrest = 0
+        for record in self.fiscal_line_ids:
+            vPrest += record.cte40_vTPrest
+        self.cte40_vPrest = vPrest
 
     # Campos do Modal Dutoviario
     cte40_dIni = fields.Date(string="Data de Início da prestação do serviço")
@@ -565,13 +567,13 @@ def _compute_vPrest(self):
 
     # TRAFMUT
     cte40_trafMut = fields.Many2one(
-        comodel_name="l10n_br_fiscal.document",
+        comodel_name="l10n_br_fiscal.document.line",
         string="Detalhamento de informações",
         help="Detalhamento de informações para o tráfego mútuo",
     )
 
     cte40_vFrete = fields.Monetary(
-        related="cte40_trafMut.amount_freight_value",
+        related="amount_freight_value",
         currency_field="brl_currency_id",
     )
 
@@ -596,8 +598,8 @@ def _compute_vPrest(self):
     )
 
     cte40_ferroEnv = fields.One2many(
-        comodel_name="l10n_br_cte.ferroenv",
-        inverse_name="cte40_cInt",
+        comodel_name="l10n_br_cte.modal.ferroviario.trafmut.ferroenv",
+        inverse_name="document_id",
         string="Informações das Ferrovias Envolvidas",
     )
 
@@ -605,13 +607,13 @@ def _compute_vPrest(self):
     cte40_RNTRC = fields.Char(
         string="RNTRC",
         store=True,
-        related="document_id.cte40_emit.partner_id.rntrc_code",
+        related="partner_id.rntrc_code",
         help="Registro Nacional de Transportadores Rodoviários de Carga",
     )
 
     cte40_occ = fields.One2many(
-        comodel_name="l10n_br_cte.occ",
-        inverse_name="cte40_occ_rodo_id",
+        comodel_name="l10n_br_cte.modal.rodoviario.occ",
+        inverse_name="document_id",
         string="Ordens de Coleta associados",
     )
 
@@ -620,40 +622,6 @@ def _compute_vPrest(self):
     # Compute Methods
     ##########################
 
-    def _compute_modal(self):
-        if self.cte40_modal == "1":
-            self.cte40_infModal = self.cte40_rodoviario
-        elif self.cte40_modal == "2":
-            self.cte40_infModal = self.cte40_aereo
-        elif self.cte40_modal == "3":
-            self.cte40_infModal = self.cte40_aquav
-        elif self.cte40_modal == "4":
-            self.cte40_infModal = self.cte40_ferroviario
-        elif self.cte40_modal == "5":
-            self.cte40_infModal = self.cte40_dutoviario
-        elif self.cte40_modal == "6":
-            pass  # TODO
-
-    cte40_aquav = fields.Many2one(
-        comodel_name="l10n_br_cte.aquaviario", inverse_name="document_id"
-    )
-
-    cte40_dutoviario = fields.Many2one(
-        comodel_name="l10n_br_cte.dutoviario", inverse_name="document_id"
-    )
-
-    cte40_rodoviario = fields.Many2one(
-        comodel_name="l10n_br_cte.rodoviario", inverse_name="document_id"
-    )
-
-    cte40_ferroviario = fields.Many2one(
-        comodel_name="l10n_br_cte.ferroviario", inverse_name="document_id"
-    )
-
-    cte40_aereo = fields.Many2one(
-        comodel_name="l10n_br_cte.aereo", inverse_name="document_id"
-    )
-
     ################################
     # Business Model Methods
     ################################
diff --git a/l10n_br_cte/models/ferroviario.py b/l10n_br_cte/models/ferroviario.py
index 117fc61c01a1..658fd27dfa0c 100644
--- a/l10n_br_cte/models/ferroviario.py
+++ b/l10n_br_cte/models/ferroviario.py
@@ -39,9 +39,9 @@ class Ferroviario(spec_models.SpecModel):
 
 class TrafMut(spec_models.SpecModel):
     _name = "l10n_br_cte.modal.ferroviario.trafmut"
+    _inherit = "cte.40.trafmut"
 
     cte40_vFrete = fields.Monetary(
-        related="cte40_trafMut.amount_freight_value",
         currency_field="brl_currency_id",
     )
 
@@ -67,7 +67,6 @@ class TrafMut(spec_models.SpecModel):
 
     cte40_ferroEnv = fields.One2many(
         comodel_name="l10n_br_cte.modal.ferroviario.trafmut.ferroenv",
-        inverse_name="document_id",
         string="Informações das Ferrovias Envolvidas",
     )
 
@@ -113,7 +112,7 @@ def export_fields_multi(self):
 
 class TenderFerrov(spec_models.SpecModel):
     _name = "l10n_br_cte.modal.tenderfer"
-    _inherit = "spec.mixin.cte"
+    _inherit = "cte.40.tenderfer"
 
     cte40_xLgr = fields.Char(string="Logradouro")
 
diff --git a/l10n_br_cte/models/rodoviario.py b/l10n_br_cte/models/rodoviario.py
index 5a6f4b742863..ead93eb7c5ac 100644
--- a/l10n_br_cte/models/rodoviario.py
+++ b/l10n_br_cte/models/rodoviario.py
@@ -12,20 +12,14 @@ class Rodoviario(spec_models.SpecModel):
     _name = "l10n_br_cte.modal.rodoviario"
     _inherit = "cte.40.rodo"
 
-    document_id = fields.One2many(
-        comodel_name="l10n_br_fiscal.document", inverse_name="cte40_rodoviario"
-    )
-
     cte40_RNTRC = fields.Char(
         string="RNTRC",
         store=True,
-        related="document_id.cte40_emit.partner_id.rntrc_code",
         help="Registro Nacional de Transportadores Rodoviários de Carga",
     )
 
     cte40_occ = fields.One2many(
         comodel_name="l10n_br_cte.modal.rodoviario.occ",
-        inverse_name="document_id",
         string="Ordens de Coleta associados",
     )