diff --git a/README.md b/README.md
index 98289f2..85306e3 100644
--- a/README.md
+++ b/README.md
@@ -25,14 +25,16 @@ The following resources will be created:
 | Name | Version |
 |------|---------|
 | aws | n/a |
+| random | n/a |
 
 ## Inputs
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
-| account\_ids | List of accounts to allow publishing to SNS | `list(string)` | `[]` | no |
+| account\_ids | List of accounts to allow publishing to SNS (optional - only when SNS topic is created) | `list(string)` | `[]` | no |
 | slack\_endpoint | endpoint to Slack notifications chanel | `string` | `""` | no |
-| topic\_name | Topic name | `any` | n/a | yes |
+| sns\_topic\_arn | SNS Topic to use instead of creating one (optional) | `string` | `""` | no |
+| sns\_topic\_name | Topic name (optional - creates SNS topic) | `string` | `""` | no |
 
 ## Outputs