diff --git a/facho/fe/model/__init__.py b/facho/fe/model/__init__.py
index 5de325e..504c644 100644
--- a/facho/fe/model/__init__.py
+++ b/facho/fe/model/__init__.py
@@ -38,9 +38,9 @@ class Time(model.Model):
 class InvoicePeriod(model.Model):
     __name__ = 'InvoicePeriod'
 
-    start_date = fields.Many2One(Date, name='StartDate')
+    start_date = fields.Many2One(Date, name='StartDate', namespace='cbc')
 
-    end_date = fields.Many2One(Date, name='EndDate')
+    end_date = fields.Many2One(Date, name='EndDate', namespace='cbc')
 
 class ID(model.Model):
     __name__ = 'ID'
@@ -51,15 +51,27 @@ class ID(model.Model):
     def __str__(self):
         return str(self._value)
 
+class PartyTaxScheme(model.Model):
+    __name__ = 'PartyTaxScheme'
+
+    company_id = fields.Many2One(ID, name='CompanyID', namespace='cbc')
+    tax_level_code = fields.Many2One(ID, name='TaxLevelCode', namespace='cbc', default='ZZ')
+    
 class Party(model.Model):
     __name__ = 'Party'
 
-    id = fields.Many2One(ID)
+    id = fields.Virtual(setter='set_id')
+
+    tax_scheme = fields.Many2One(PartyTaxScheme, namespace='cac')
+
+    def set_id(self, name, value):
+        self.tax_scheme.company_id = value
+        return value
 
 class AccountingCustomerParty(model.Model):
     __name__ = 'AccountingCustomerParty'
 
-    party = fields.Many2One(Party)
+    party = fields.Many2One(Party, namespace='cac')
 
 class AccountingSupplierParty(model.Model):
     __name__ = 'AccountingSupplierParty'
@@ -100,7 +112,7 @@ class Amount(model.Model):
 class Price(model.Model):
     __name__ = 'Price'
 
-    amount = fields.Many2One(Amount, name='PriceAmount')
+    amount = fields.Many2One(Amount, name='PriceAmount', namespace='cbc')
     
     def __default_set__(self, value):
         self.amount = value
@@ -115,14 +127,14 @@ class Percent(model.Model):
 class TaxScheme(model.Model):
     __name__ = 'TaxScheme'
 
-    id = fields.Many2One(ID)
-    name= fields.Many2One(Name)
+    id = fields.Many2One(ID, namespace='cbc')
+    name= fields.Many2One(Name, namespace='cbc')
 
 class TaxCategory(model.Model):
     __name__ = 'TaxCategory'
 
-    percent = fields.Many2One(Percent)
-    tax_scheme = fields.Many2One(TaxScheme)
+    percent = fields.Many2One(Percent, namespace='cbc')
+    tax_scheme = fields.Many2One(TaxScheme, namespace='cac')
     
 class TaxSubTotal(model.Model):
     __name__ = 'TaxSubTotal'
@@ -154,14 +166,14 @@ class TaxSubTotal(model.Model):
 class TaxTotal(model.Model):
     __name__ = 'TaxTotal'
 
-    tax_amount = fields.Many2One(Amount, name='TaxAmount', default=0.00)
-    subtotals = fields.One2Many(TaxSubTotal)
+    tax_amount = fields.Many2One(Amount, name='TaxAmount', namespace='cbc', default=0.00)
+    subtotals = fields.One2Many(TaxSubTotal, namespace='cac')
 
 
 class AllowanceCharge(model.Model):
     __name__ = 'AllowanceCharge'
 
-    amount = fields.Many2One(Amount)
+    amount = fields.Many2One(Amount, namespace='cbc')
     is_discount = fields.Virtual(default=False)
     
     def isCharge(self):
@@ -186,11 +198,12 @@ class Taxes:
 class InvoiceLine(model.Model):
     __name__ = 'InvoiceLine'
 
-    quantity = fields.Many2One(Quantity, name='InvoicedQuantity')
-    taxtotal = fields.Many2One(TaxTotal)
-    price = fields.Many2One(Price)
-    amount = fields.Many2One(Amount, name='LineExtensionAmount')
-    allowance_charge = fields.One2Many(AllowanceCharge)
+    id = fields.Many2One(ID, namespace='cbc')
+    quantity = fields.Many2One(Quantity, name='InvoicedQuantity', namespace='cbc')
+    taxtotal = fields.Many2One(TaxTotal, namespace='cac')
+    price = fields.Many2One(Price, namespace='cac')
+    amount = fields.Many2One(Amount, name='LineExtensionAmount', namespace='cbc')
+    allowance_charge = fields.One2Many(AllowanceCharge, 'cac')
     tax_amount = fields.Virtual(getter='get_tax_amount')
     
     def __setup__(self):
@@ -242,12 +255,12 @@ class InvoiceLine(model.Model):
 class LegalMonetaryTotal(model.Model):
     __name__ = 'LegalMonetaryTotal'
 
-    line_extension_amount = fields.Many2One(Amount, name='LineExtensionAmount', default=0)
+    line_extension_amount = fields.Many2One(Amount, name='LineExtensionAmount', namespace='cbc', default=0)
 
-    tax_exclusive_amount = fields.Many2One(Amount, name='TaxExclusiveAmount', default=form.Amount(0))
-    tax_inclusive_amount = fields.Many2One(Amount, name='TaxInclusiveAmount', default=form.Amount(0))
-    charge_total_amount = fields.Many2One(Amount, name='ChargeTotalAmount', default=form.Amount(0))
-    payable_amount = fields.Many2One(Amount, name='PayableAmount', default=form.Amount(0))
+    tax_exclusive_amount = fields.Many2One(Amount, name='TaxExclusiveAmount', namespace='cbc', default=form.Amount(0))
+    tax_inclusive_amount = fields.Many2One(Amount, name='TaxInclusiveAmount', namespace='cbc', default=form.Amount(0))
+    charge_total_amount = fields.Many2One(Amount, name='ChargeTotalAmount', namespace='cbc', default=form.Amount(0))
+    payable_amount = fields.Many2One(Amount, name='PayableAmount', namespace='cbc', default=form.Amount(0))
 
     @fields.on_change(['tax_inclusive_amount', 'charge_total'])
     def update_payable_amount(self, name, value):
@@ -255,18 +268,27 @@ class LegalMonetaryTotal(model.Model):
 
 class Invoice(model.Model):
     __name__ = 'Invoice'
-
-    id = fields.Many2One(ID)
-    issue = fields.Virtual(setter='set_issue')
-    issue_date = fields.Many2One(Date, name='IssueDate')
-    issue_time = fields.Many2One(Time, name='IssueTime')
+    __namespace__ = {
+        'cac': 'urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2',
+        'cbc': 'urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2',
+        'cdt': 'urn:DocumentInformation:names:specification:ubl:colombia:schema:xsd:DocumentInformationAggregateComponents-1',
+        'ext': 'urn:oasis:names:specification:ubl:schema:xsd:CommonExtensionComponents-2',
+        'sts': 'http://www.dian.gov.co/contratos/facturaelectronica/v1/Structures',
+        'xades': 'http://uri.etsi.org/01903/v1.3.2#',
+        'ds': 'http://www.w3.org/2000/09/xmldsig#'
+    }
     
-    period = fields.Many2One(InvoicePeriod)
+    id = fields.Many2One(ID, namespace='cbc')
+    issue = fields.Virtual(setter='set_issue')
+    issue_date = fields.Many2One(Date, name='IssueDate', namespace='cbc')
+    issue_time = fields.Many2One(Time, name='IssueTime', namespace='cbc')
+    
+    period = fields.Many2One(InvoicePeriod, namespace='cac')
 
-    supplier = fields.Many2One(AccountingSupplierParty)
-    customer = fields.Many2One(AccountingCustomerParty)
-    lines = fields.One2Many(InvoiceLine)
-    legal_monetary_total = fields.Many2One(LegalMonetaryTotal)
+    supplier = fields.Many2One(AccountingSupplierParty, namespace='cac')
+    customer = fields.Many2One(AccountingCustomerParty, namespace='cac')
+    lines = fields.One2Many(InvoiceLine, namespace='cac')
+    legal_monetary_total = fields.Many2One(LegalMonetaryTotal, namespace='cac')
     
     taxtotal_01 = fields.Many2One(TaxTotal)
     taxtotal_04 = fields.Many2One(TaxTotal)
diff --git a/facho/model/fields/field.py b/facho/model/fields/field.py
index d8a6fe4..7deec60 100644
--- a/facho/model/fields/field.py
+++ b/facho/model/fields/field.py
@@ -1,3 +1,5 @@
+import warnings
+
 class Field:
     def __set_name__(self, owner, name, virtual=False):
         self.name = name
@@ -17,8 +19,10 @@ class Field:
         if name is None:
             return
 
-        if name not in namespaces:
-            raise KeyError("namespace %s not found" % (name))
+        #TODO(bit4bit) aunque las pruebas confirmar
+        #que si se escribe el namespace que es
+        #no ahi confirmacion de declaracion previa del namespace
+
         inst._namespace_prefix = name
 
     def _call(self, inst, method, *args):
@@ -27,7 +31,7 @@ class Field:
         if callable(call):
             return call(*args)
 
-    def _create_model(self, inst, name=None, model=None, attribute=None):
+    def _create_model(self, inst, name=None, model=None, attribute=None, namespace=None):
         try:
             return inst._fields[self.name]
         except KeyError:
@@ -37,7 +41,11 @@ class Field:
                 obj = self.model()
             if name is not None:
                 obj.__name__ = name
-            self._set_namespace(obj, self.namespace, inst.__namespace__)
+
+            if namespace:
+                self._set_namespace(obj, namespace, inst.__namespace__)
+            else:
+                self._set_namespace(obj, self.namespace, inst.__namespace__)
 
             if attribute:
                 inst._fields[attribute] = obj
diff --git a/facho/model/fields/one2many.py b/facho/model/fields/one2many.py
index 2c2dca7..da7960c 100644
--- a/facho/model/fields/one2many.py
+++ b/facho/model/fields/one2many.py
@@ -67,7 +67,7 @@ class One2Many(Field):
         assert self.name is not None
 
         def creator(attribute):
-            return self._create_model(inst, name=self.field_name, model=self.model, attribute=attribute)
+            return self._create_model(inst, name=self.field_name, model=self.model, attribute=attribute, namespace=self.namespace)
         
         if inst in self.relation:
             return self.relation[inst]
diff --git a/tests/test_model.py b/tests/test_model.py
index 10cc99e..0ceebec 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -195,6 +195,58 @@ def test_model_with_xml_namespace_nested():
     person.id = 33
     assert '<Person xmlns:facho="http://lib.facho.cyou"><facho:ID>33</facho:ID></Person>' == person.to_xml()
 
+def test_model_with_xml_namespace_nested_nested():
+    class ID(facho.model.Model):
+        __name__ = 'ID'
+        
+    class Party(facho.model.Model):
+        __name__ = 'Party'
+
+        id = fields.Many2One(ID, namespace='party')
+
+        def __default_set__(self, value):
+            self.id = value
+
+    class Person(facho.model.Model):
+        __name__ = 'Person'
+        __namespace__ = {
+            'person': 'http://lib.facho.cyou',
+            'party': 'http://lib.facho.cyou'
+        }
+
+        id = fields.Many2One(Party, namespace='person')
+        
+    person = Person()
+    person.id = 33
+    assert '<Person xmlns:person="http://lib.facho.cyou" xmlns:party="http://lib.facho.cyou"><person:Party><party:ID>33</party:ID></person:Party></Person>' == person.to_xml()
+
+def test_model_with_xml_namespace_nested_one_many():
+    class Name(facho.model.Model):
+        __name__ = 'Name'
+
+    class Contact(facho.model.Model):
+        __name__ = 'Contact'
+
+        name = fields.Many2One(Name, namespace='contact')
+
+    class Person(facho.model.Model):
+        __name__ = 'Person'
+        __namespace__ = {
+            'facho': 'http://lib.facho.cyou',
+            'contact': 'http://lib.facho.cyou'
+        }
+
+        contacts = fields.One2Many(Contact, namespace='facho')
+        
+    person = Person()
+    contact = person.contacts.create()
+    contact.name = 'contact1'
+
+    contact = person.contacts.create()
+    contact.name = 'contact2'
+
+    assert '<Person xmlns:facho="http://lib.facho.cyou" xmlns:contact="http://lib.facho.cyou"><facho:Contact><contact:Name>contact1</contact:Name></facho:Contact><facho:Contact><contact:Name>contact2</contact:Name></facho:Contact></Person>' == person.to_xml()
+
 def test_field_model_with_namespace():
     class ID(facho.model.Model):
         __name__ = 'ID'