diff --git a/facho/fe/client/dian.py b/facho/fe/client/dian.py
index 361ac7f..cc5bfe1 100644
--- a/facho/fe/client/dian.py
+++ b/facho/fe/client/dian.py
@@ -34,32 +34,26 @@ class SOAPService:
         return asdict(self)
 
 @dataclass
-class ConsultaResolucionesFacturacionRespuesta:
+class GetNumberingRangeResponse:
 
     @dataclass
-    class RangoFacturacion:
-        NumeroResolucion: str
-        FechaResolucion: datetime
-        Prefijo: str
-        RangoInicial: int
-        RangoFinal: int
-        FechaVigenciaDesde: datetime
-        FechaVigenciaHasta: datetime
-        ClaveTecnica: str
-        
-    CodigoOperacion: str
-    DescripcionOperacion: str
-    IdentificadorOperacion: str
-    RangoFacturacion: List[RangoFacturacion]
+    class NumberRangeResponse:
+        ResolutionNumber: str
+        ResolutionDate: str
+        Prefix: str
+        FromNumber: int
+        ToNumber: int
+        ValidateDateFrom: str
+        ValidateDateTo: str
+        TechnicalKey: str
+
+    NumberRangeResponse: List[NumberRangeResponse]
 
 
     @classmethod
     def fromdict(cls, data):
         return cls(
-            data['CodigoOperacion'],
-            data['DescripcionOperacion'],
-            data['IdentificadorOperacion'],
-            data['RangoFacturacion']
+            data['NumberRangeResponse']
         )
 
 
@@ -76,7 +70,7 @@ class GetNumberingRange(SOAPService):
         return 'GetNumberingRange'
     
     def build_response(self, as_dict):
-        return as_dict
+        return GetNumberingRangeResponse.fromdict(as_dict)
 
 
 @dataclass
diff --git a/facho/fe/form.py b/facho/fe/form.py
index d01ffda..b777844 100644
--- a/facho/fe/form.py
+++ b/facho/fe/form.py
@@ -10,11 +10,24 @@ from datetime import datetime
 from .data.dian import codelist
 from . import fe
 
+
+@dataclass
+class Item:
+    description: str
+    id: str
+
+    
+@dataclass
+class StandarItem(Item):
+    pass
+
+
 @dataclass
 class Country:
     code: str
     name: str
 
+    
 @dataclass
 class Address:
     name: str
@@ -22,6 +35,7 @@ class Address:
     city: str = ''
     department: str = ''
     country: Country = Country('CO', 'COLOMBIA')
+
     
 @dataclass
 class Party:
@@ -38,7 +52,6 @@ class Party:
     legal_address: str = ''
 
 
-
 @dataclass
 class TaxSubTotal:
     percent: float
@@ -70,7 +83,7 @@ class InvoiceLine:
     # RESOLUCION 0004: pagina 155
     quantity: int
     description: str
-    item_ident: int
+    item: Item
     price_amount: float
     tax: TaxTotal
 
@@ -157,26 +170,26 @@ class DianResolucion0001Validator:
     def __init__(self):
         self.errors = []
 
-    def _validate_party(self, party):
+    def _validate_party(self, model, party):
         try:
             codelist.TipoResponsabilidad[party.responsability_code]
         except KeyError:
-            self.errors.append(('responsability_code', 'not found'))
+            self.errors.append((model, 'responsability_code', 'not found'))
 
         try:
             codelist.TipoOrganizacion[party.organization_code]
         except KeyError:
-            self.errors.append(('organization_code', 'not found'))
+            self.errors.append((model, 'organization_code', 'not found'))
 
     def validate(self, invoice):
         invoice.accept(self)
         return not self.errors
 
     def visit_customer(self, customer):
-        self._validate_party(customer)
+        self._validate_party('customer', customer)
 
     def visit_supplier(self, supplier):
-        self._validate_party(supplier)
+        self._validate_party('supplier', supplier)
 
     def visit_invoice_line(self, line):
         pass
@@ -276,7 +289,8 @@ class DIANInvoiceXML(fe.FeXML):
             line.set_element('/fe:InvoiceLine/cbc:InvoicedQuantity', invoice_line.quantity, unitCode = 'NAR')
             line.set_element('/fe:InvoiceLine/cbc:LineExtensionAmount', invoice_line.total_amount, currencyID="COP")
             line.set_element('/fe:InvoiceLine/fe:Price/cbc:PriceAmount', invoice_line.price_amount, currencyID="COP") 
-            line.set_element('/fe:InvoiceLine/fe:Item/cbc:Description', invoice_line.description)
-
+            line.set_element('/fe:InvoiceLine/fe:Item/cbc:Description', invoice_line.item.description)
+            # TODO
+            line.set_element('/fe:InvoiceLine/fe:Item/cac:StandardItemIdentification/cbc:ID', invoice_line.item.id) 
 
         return fexml
diff --git a/tests/test_fe_form.py b/tests/test_fe_form.py
index 8b0ffb8..7ea2c1a 100644
--- a/tests/test_fe_form.py
+++ b/tests/test_fe_form.py
@@ -57,7 +57,7 @@ def simple_invoice():
     inv.add_invoice_line(form.InvoiceLine(
         quantity = 1,
         description = 'producto facho',
-        item_ident = 9999,
+        item = form.StandarItem('test', 9999),
         price_amount = 100.0,
         tax = form.TaxTotal(
             tax_amount = 0.0,
@@ -159,7 +159,7 @@ def test_invoice_totals(simple_invoice_without_lines):
     simple_invoice.add_invoice_line(form.InvoiceLine(
         quantity = 1,
         description = 'producto',
-        item_ident = 9999,
+        item = form.StandarItem('test', 9999),
         price_amount = 1_500_000,
         tax = form.TaxTotal(
             subtotals = [
@@ -182,7 +182,7 @@ def test_invoice_cufe(simple_invoice_without_lines):
     simple_invoice.add_invoice_line(form.InvoiceLine(
         quantity = 1,
         description = 'producto',
-        item_ident = 9999,
+        item = form.StandarItem('test', 111),
         price_amount = 1_500_000,
         tax = form.TaxTotal(
             subtotals = [