diff --git a/db/procedures/add_person_to_lease.sql b/db/procedures/add_person_to_lease.sql
new file mode 100644
index 0000000..83ed58c
--- /dev/null
+++ b/db/procedures/add_person_to_lease.sql
@@ -0,0 +1,22 @@
+CREATE OR REPLACE PROCEDURE add_person_to_lease (
+	pid IN person.id%type,
+	lid IN lease.id%type,
+	success OUT number
+) IS
+	valid number;
+BEGIN
+	-- Check if lease is valid
+	SELECT COUNT(*) INTO valid
+	FROM lease join person_on_lease on lease.id = person_on_lease.person_id
+	WHERE
+		lease.id = lid AND person_id <> pid AND
+		CURRENT_TIMESTAMP >= ADD_MONTHS(start_date, term_length);
+
+	IF valid <> 0 THEN
+		success := 1;
+		return;
+	END IF;
+
+	INSERT INTO person_on_lease VALUES(lid, pid);
+	success := 0;
+END;