diff --git a/lib/lob/resource_base.ex b/lib/lob/resource_base.ex
index 4e6c3fc..8e24bab 100644
--- a/lib/lob/resource_base.ex
+++ b/lib/lob/resource_base.ex
@@ -18,6 +18,14 @@ defmodule Lob.ResourceBase do
         def list(params \\ %{}, headers \\ %{}) do
           Client.get_request("#{base_url()}?#{Util.build_query_string(params)}" , Util.build_headers(headers))
         end
+
+        @spec list!(map, map) :: {map, list} | no_return
+        def list!(params \\ %{}, headers \\ %{}) do
+          case list(params, headers) do
+            {:ok, body, headers} -> {body, headers}
+            {:error, error} -> raise to_string(error)
+          end
+        end
       end
 
       if :retrieve in unquote(methods) do
@@ -25,6 +33,14 @@ defmodule Lob.ResourceBase do
         def retrieve(id, headers \\ %{}) do
           Client.get_request(resource_url(id), Util.build_headers(headers))
         end
+
+        @spec retrieve!(String.t, map) :: {map, list} | no_return
+        def retrieve!(id, headers \\ %{}) do
+          case retrieve(id, headers) do
+            {:ok, body, headers} -> {body, headers}
+            {:error, error} -> raise to_string(error)
+          end
+        end
       end
 
       if :create in unquote(methods) do
@@ -32,6 +48,14 @@ defmodule Lob.ResourceBase do
         def create(data, headers \\ %{}) do
           Client.post_request(base_url(), Util.build_body(data), Util.build_headers(headers))
         end
+
+        @spec create!(map, map) :: {map, list} | no_return
+        def create!(data, headers \\ %{}) do
+          case create(data, headers) do
+            {:ok, body, headers} -> {body, headers}
+            {:error, error} -> raise to_string(error)
+          end
+        end
       end
 
       if :delete in unquote(methods) do
@@ -39,6 +63,14 @@ defmodule Lob.ResourceBase do
         def delete(id, headers \\ %{}) do
           Client.delete_request(resource_url(id), Util.build_headers(headers))
         end
+
+        @spec delete!(String.t, map) :: {map, list} | no_return
+        def delete!(id, headers \\ %{}) do
+          case delete(id, headers) do
+            {:ok, body, headers} -> {body, headers}
+            {:error, error} -> raise to_string(error)
+          end
+        end
       end
 
       @spec base_url :: String.t
diff --git a/lib/lob/util.ex b/lib/lob/util.ex
index 859be21..0d0e23a 100644
--- a/lib/lob/util.ex
+++ b/lib/lob/util.ex
@@ -38,7 +38,7 @@ defmodule Lob.Util do
     iex> Lob.Util.build_headers(%{"Idempotency-Key" => "abc123", "Lob-Version" => "2017-11-08"})
     [{"Idempotency-Key", "abc123"}, {"Lob-Version", "2017-11-08"}]
   """
-  @spec build_headers(list({any, any})) :: HTTPoison.Base.headers
+  @spec build_headers(map) :: HTTPoison.Base.headers
   def build_headers(headers) do
     headers
     |> Enum.to_list