diff --git a/.changelog/25645.txt b/.changelog/25645.txt
new file mode 100644
index 000000000000..8f6a002356e7
--- /dev/null
+++ b/.changelog/25645.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_cognito_risk_configuration: Increase maximum allowed length of `account_takeover_risk_configuration.notify_configuration.block_email.html_body`, `account_takeover_risk_configuration.notify_configuration.block_email.text_body`, `account_takeover_risk_configuration.notify_configuration.mfa_email.html_body`, `account_takeover_risk_configuration.notify_configuration.mfa_email.text_body`, `account_takeover_risk_configuration.notify_configuration.no_action_email.html_body` and `account_takeover_risk_configuration.notify_configuration.no_action_email.text_body` arguments from `2000` to `20000`
+```
diff --git a/internal/service/cognitoidp/risk_configuration.go b/internal/service/cognitoidp/risk_configuration.go
index 37dd28adda0b..bfcb1ad9ded0 100644
--- a/internal/service/cognitoidp/risk_configuration.go
+++ b/internal/service/cognitoidp/risk_configuration.go
@@ -121,7 +121,7 @@ func ResourceRiskConfiguration() *schema.Resource {
 												"html_body": {
 													Type:         schema.TypeString,
 													Required:     true,
-													ValidateFunc: validation.StringLenBetween(6, 2000),
+													ValidateFunc: validation.StringLenBetween(6, 20000),
 												},
 												"subject": {
 													Type:         schema.TypeString,
@@ -131,7 +131,7 @@ func ResourceRiskConfiguration() *schema.Resource {
 												"text_body": {
 													Type:         schema.TypeString,
 													Required:     true,
-													ValidateFunc: validation.StringLenBetween(6, 2000),
+													ValidateFunc: validation.StringLenBetween(6, 20000),
 												},
 											},
 										},
@@ -149,7 +149,7 @@ func ResourceRiskConfiguration() *schema.Resource {
 												"html_body": {
 													Type:         schema.TypeString,
 													Required:     true,
-													ValidateFunc: validation.StringLenBetween(6, 2000),
+													ValidateFunc: validation.StringLenBetween(6, 20000),
 												},
 												"subject": {
 													Type:         schema.TypeString,
@@ -159,7 +159,7 @@ func ResourceRiskConfiguration() *schema.Resource {
 												"text_body": {
 													Type:         schema.TypeString,
 													Required:     true,
-													ValidateFunc: validation.StringLenBetween(6, 2000),
+													ValidateFunc: validation.StringLenBetween(6, 20000),
 												},
 											},
 										},
@@ -173,7 +173,7 @@ func ResourceRiskConfiguration() *schema.Resource {
 												"html_body": {
 													Type:         schema.TypeString,
 													Required:     true,
-													ValidateFunc: validation.StringLenBetween(6, 2000),
+													ValidateFunc: validation.StringLenBetween(6, 20000),
 												},
 												"subject": {
 													Type:         schema.TypeString,
@@ -183,7 +183,7 @@ func ResourceRiskConfiguration() *schema.Resource {
 												"text_body": {
 													Type:         schema.TypeString,
 													Required:     true,
-													ValidateFunc: validation.StringLenBetween(6, 2000),
+													ValidateFunc: validation.StringLenBetween(6, 20000),
 												},
 											},
 										},
diff --git a/website/docs/r/cognito_risk_configuration.html.markdown b/website/docs/r/cognito_risk_configuration.html.markdown
index 82ba6bd77fd3..e2a6b4a06e8b 100644
--- a/website/docs/r/cognito_risk_configuration.html.markdown
+++ b/website/docs/r/cognito_risk_configuration.html.markdown
@@ -49,8 +49,8 @@ The following arguments are supported:
 ##### notify email type
 
 * `html_body` - (Required) The email HTML body.
-* `block_email` - (Required) The email subject.
-* `block_email` - (Required) The email text body.
+* `subject` - (Required) The email subject.
+* `test_body` - (Required) The email text body.
 
 #### actions