diff --git a/lib/get_geocode.ex b/lib/get_geocode.ex
index 5e871f7..38a1532 100644
--- a/lib/get_geocode.ex
+++ b/lib/get_geocode.ex
@@ -19,13 +19,21 @@ defmodule GetGeocode do
   end
 
   defp get_viacep(cep) do
-    ViaCep.get_cep(cep)
-    |> builder_from_viacep()
+    result = ViaCep.get_cep(cep)
+
+    case result do
+      %{"erro" => _} -> msg_invalid_input()
+      _ -> builder_from_viacep(result)
+    end
   end
 
   defp get_nominatim(addr) do
-    Nominatim.get_data(addr)
-    |> builder_from_nominatim()
+    result = Nominatim.get_data(addr)
+
+    case result do
+      {_, _} -> result
+      _ -> builder_from_nominatim(result)
+    end
   end
 
   defp addr?(addr) do
diff --git a/lib/get_geocode/apis/nominatim.ex b/lib/get_geocode/apis/nominatim.ex
index 77c6303..85a3591 100644
--- a/lib/get_geocode/apis/nominatim.ex
+++ b/lib/get_geocode/apis/nominatim.ex
@@ -1,11 +1,39 @@
 defmodule GetGeocode.Apis.Nominatim do
+  @moduledoc """
+  ## Nominatim API.
+  """
   @url "https://nominatim.openstreetmap.org/search?q=<QUERY>&format=json"
 
+  @doc """
+  Gets data from an `addr`ess.
+
+  Results in a list with the data, or a tuple `{:ok, "No result"}`.
+
+  ## Examples
+    iex> GetGeocode.Apis.Nominatim.get_data "Rua Izaurina Braga"
+    %{
+      "boundingbox" => ["-3.1058605", "-3.105157", "-60.0550895", "-60.0542833"],
+      "class" => "highway",
+      "display_name" => "Rua Izaurina Braga, Compensa, Manaus, Região Geográfica Imediata de Manaus, Região Geográfica Intermediária de Manaus, Amazonas, Região Norte, 69000-000, Brasil",
+      "importance" => 0.4,
+      "lat" => "-3.1054153",
+      "licence" => "Data © OpenStreetMap contributors, ODbL 1.0. https://osm.org/copyright",
+      "lon" => "-60.0547259",
+      "osm_id" => 662237608,
+      "osm_type" => "way",
+      "place_id" => 233020447,
+      "type" => "residential"
+      }
+  """
   def get_data(addr) do
     {:ok, %HTTPoison.Response{body: body}} = HTTPoison.get(gen_query(addr))
 
-    Jason.decode!(body)
-    |> hd()
+    result = Jason.decode!(body)
+
+    case result do
+      [] -> {:ok, "No result"}
+      _ -> hd(result)
+    end
   end
 
   defp sanitize(query) do
diff --git a/lib/get_geocode/apis/via_cep.ex b/lib/get_geocode/apis/via_cep.ex
index ee97e31..102c9a1 100644
--- a/lib/get_geocode/apis/via_cep.ex
+++ b/lib/get_geocode/apis/via_cep.ex
@@ -1,14 +1,21 @@
 defmodule GetGeocode.Apis.ViaCep do
   @moduledoc """
       ## ViaCEP API
-      ### https://viacep.com.br/ws/
+      From https://viacep.com.br/
   """
   @url "https://viacep.com.br/ws"
 
-  def get_cep(cep) do
-    cep = sanitize(cep)
-    {:ok, %HTTPoison.Response{body: body}} = HTTPoison.get("#{@url}/#{cep}/json")
-    Jason.decode!(body)
+  def get_cep(cep) when is_binary(cep) do
+    cep_sanitized = sanitize(cep)
+
+    cond do
+      String.length(cep_sanitized) == 8 -> send_request(cep_sanitized)
+      true -> {:error, "CEP must be 8 digits long"}
+    end
+  end
+
+  def get_cep(_) do
+    {:error, "CEP must be a string with 8 digits"}
   end
 
   defp sanitize(cep) do
@@ -17,4 +24,9 @@ defmodule GetGeocode.Apis.ViaCep do
     |> String.replace("-", "")
     |> String.replace(" ", "")
   end
+
+  defp send_request(cep) do
+    {:ok, %HTTPoison.Response{body: body}} = HTTPoison.get("#{@url}/#{cep}/json")
+    Jason.decode!(body)
+  end
 end
diff --git a/lib/get_geocode/application.ex b/lib/get_geocode/application.ex
index 36dd6c7..3857fdf 100644
--- a/lib/get_geocode/application.ex
+++ b/lib/get_geocode/application.ex
@@ -8,7 +8,7 @@ defmodule GetGeocode.Application do
   def start(_type, _args) do
     children = [
       # Starts a worker by calling: GetGeocode.Worker.start_link(arg)
-      # {GetGeocode.Worker, arg}
+      # {GetGeocodeCash, %{}}
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html
diff --git a/test/apis/via_cep_test.exs b/test/apis/via_cep_test.exs
index 2a0ba93..a08adc3 100644
--- a/test/apis/via_cep_test.exs
+++ b/test/apis/via_cep_test.exs
@@ -6,4 +6,14 @@ defmodule GetGeocodeApisViaCepTest do
     %{"localidade" => cidade} = ViaCep.get_cep("69035350")
     assert cidade == "Manaus"
   end
+
+  test "get_cep/1 with input other than string" do
+    result = ViaCep.get_cep(1)
+    assert result == {:error, "CEP must be a string with 8 digits"}
+  end
+
+  test "get_cep/1 with input less than 8 digits" do
+    result = ViaCep.get_cep("690353")
+    assert result == {:error, "CEP must be 8 digits long"}
+  end
 end
diff --git a/test/getgeocode_test.exs b/test/getgeocode_test.exs
index 16e94bd..7990892 100644
--- a/test/getgeocode_test.exs
+++ b/test/getgeocode_test.exs
@@ -16,8 +16,24 @@ defmodule GetGeocodeTest do
     error = get(1)
     assert error == {:error, "Invalid input"}
   end
-  test "get/0 returning error message in no input suplied" do
+
+  test "get/0 returning error message with no input supplied" do
     error = get()
     assert error == {:error, "Invalid input"}
   end
+
+  test "get/1 returning 'No result' return from nominatim" do
+    error = get("asdasdasd asdasdasd")
+    assert error == {:ok, "No result"}
+  end
+
+  test "get/1 returning error from viacep with CEP invalid" do
+    error = get("12345678")
+    assert error == {:error, "Invalid input"}
+  end
+
+  test "get/1 returning error 'cause the input is neither cep nor the address " do
+    error = get("asdasdasdasdasdasdasdasdasd")
+    assert error == {:error, "Invalid input"}
+  end
 end
diff --git a/test/struct_test.exs b/test/struct_test.exs
index d07a17e..1957094 100644
--- a/test/struct_test.exs
+++ b/test/struct_test.exs
@@ -2,4 +2,10 @@ defmodule StructTest do
   @moduledoc """
   ## TODO
   """
+  use ExUnit.Case, async: true
+
+  test "init struct Geocode" do
+    struct_geocode = %GetGeocode.Geocode{}
+    assert Map.has_key?(struct_geocode, :postalcode)
+  end
 end