diff --git a/13_4_Paying_a_Invoice.md b/13_5_Paying_a_Invoice.md
similarity index 99%
rename from 13_4_Paying_a_Invoice.md
rename to 13_5_Paying_a_Invoice.md
index 04c1df8..b587918 100644
--- a/13_4_Paying_a_Invoice.md
+++ b/13_5_Paying_a_Invoice.md
@@ -1,4 +1,4 @@
-# 13.4: Paying a Invoice
+# 13.5: Paying a Invoice
 
 > :information_source: **NOTE:** This is a draft in progress, so that I can get some feedback from early reviewers. It is not yet ready for learning.