diff --git a/db/migrate/20180126104536_change_contacts_code_to_not_null.rb b/db/migrate/20180126104536_change_contacts_code_to_not_null.rb
new file mode 100644
index 000000000..fc1c653e2
--- /dev/null
+++ b/db/migrate/20180126104536_change_contacts_code_to_not_null.rb
@@ -0,0 +1,5 @@
+class ChangeContactsCodeToNotNull < ActiveRecord::Migration
+  def change
+    change_column_null :contacts, :code, false
+  end
+end
diff --git a/db/migrate/20180126104903_add_unique_constraint_to_contacts_code.rb b/db/migrate/20180126104903_add_unique_constraint_to_contacts_code.rb
new file mode 100644
index 000000000..2e7e7e12b
--- /dev/null
+++ b/db/migrate/20180126104903_add_unique_constraint_to_contacts_code.rb
@@ -0,0 +1,13 @@
+class AddUniqueConstraintToContactsCode < ActiveRecord::Migration
+  def up
+    execute <<-SQL
+      ALTER TABLE contacts ADD CONSTRAINT unique_contact_code UNIQUE (code)
+    SQL
+  end
+
+  def down
+    execute <<-SQL
+      ALTER TABLE contacts DROP CONSTRAINT unique_contact_code
+    SQL
+  end
+end
diff --git a/db/structure.sql b/db/structure.sql
index 2bf928769..8b13aa4a4 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -644,7 +644,7 @@ ALTER SEQUENCE contact_statuses_id_seq OWNED BY contact_statuses.id;
 
 CREATE TABLE contacts (
     id integer NOT NULL,
-    code character varying,
+    code character varying NOT NULL,
     phone character varying,
     email character varying,
     fax character varying,
@@ -3627,6 +3627,14 @@ ALTER TABLE ONLY settings
     ADD CONSTRAINT settings_pkey PRIMARY KEY (id);
 
 
+--
+-- Name: unique_contact_code; Type: CONSTRAINT; Schema: public; Owner: -; Tablespace: 
+--
+
+ALTER TABLE ONLY contacts
+    ADD CONSTRAINT unique_contact_code UNIQUE (code);
+
+
 --
 -- Name: unique_zone_origin; Type: CONSTRAINT; Schema: public; Owner: -; Tablespace: 
 --
@@ -5068,3 +5076,7 @@ INSERT INTO schema_migrations (version) VALUES ('20180123170112');
 
 INSERT INTO schema_migrations (version) VALUES ('20180125092422');
 
+INSERT INTO schema_migrations (version) VALUES ('20180126104536');
+
+INSERT INTO schema_migrations (version) VALUES ('20180126104903');
+