diff --git a/doc/Extensions/Billing-Module.md b/doc/Extensions/Billing-Module.md
index 68ace18ba..056a73523 100644
--- a/doc/Extensions/Billing-Module.md
+++ b/doc/Extensions/Billing-Module.md
@@ -1,5 +1,9 @@
 # Billing Module
 
+With the billing module you can create a bill, assign a quota to it and add ports to it.  
+It then tracks the ports usage and shows you the usage in the bill, including any overage.  
+Accounting by both total transferred data and 95th percentile is supported.
+
 To enable and use the billing module you need to perform the following steps:
 
 Edit `config.php` and add (or enable) the following line near the end of the config
@@ -29,4 +33,4 @@ $config['billing_data_purge'] = 12;     // Number of months to retain
 
 Data for the last complete billing cycle will always be retained - only data older than
 this by the configured number of months will be removed.  This task is performed in the
-daily cleanup tasks.
\ No newline at end of file
+daily cleanup tasks.