diff --git a/lib/AlipayAccount.php b/lib/AlipayAccount.php
index a79705fa4..fbb13103b 100644
--- a/lib/AlipayAccount.php
+++ b/lib/AlipayAccount.php
@@ -47,8 +47,9 @@ public function instanceUrl()
      */
     public static function retrieve($_id, $_opts = null)
     {
-        $msg = "Alipay accounts cannot be accessed without a customer ID. " .
-               "Retrieve an Alipay account using \$customer->sources->retrieve('alipay_account_id') instead.";
+        $msg = "Alipay accounts cannot be retrieved without a customer ID. " .
+               "Retrieve an Alipay account using `Customer::retrieveSource(" .
+               "'customer_id', 'alipay_account_id')`.";
         throw new Error\InvalidRequest($msg, null);
     }
 
@@ -64,8 +65,9 @@ public static function retrieve($_id, $_opts = null)
      */
     public static function update($_id, $_params = null, $_options = null)
     {
-        $msg = "Alipay accounts cannot be accessed without a customer ID. " .
-               "Call save() on \$customer->sources->retrieve('alipay_account_id') instead.";
+        $msg = "Alipay accounts cannot be updated without a customer ID. " .
+               "Update an Alipay account using `Customer::updateSource(" .
+               "'customer_id', 'alipay_account_id', \$updateParams)`.";
         throw new Error\InvalidRequest($msg, null);
     }
 }
diff --git a/lib/BankAccount.php b/lib/BankAccount.php
index a77f3054b..ca019c2c7 100644
--- a/lib/BankAccount.php
+++ b/lib/BankAccount.php
@@ -71,9 +71,11 @@ public function instanceUrl()
      */
     public static function retrieve($_id, $_opts = null)
     {
-        $msg = "Bank accounts cannot be accessed without a customer ID or account ID. " .
-               "Retrieve a bank account using \$customer->sources->retrieve('bank_account_id') or " .
-               "\$account->external_accounts->retrieve('bank_account_id') instead.";
+        $msg = "Bank accounts cannot be retrieved without a customer ID or " .
+               "an account ID. Retrieve a bank account using " .
+               "`Customer::retrieveSource('customer_id', " .
+               "'bank_account_id')` or `Account::retrieveExternalAccount(" .
+               "'account_id', 'bank_account_id')`.";
         throw new Error\InvalidRequest($msg, null);
     }
 
@@ -86,9 +88,11 @@ public static function retrieve($_id, $_opts = null)
      */
     public static function update($_id, $_params = null, $_options = null)
     {
-        $msg = "Bank accounts cannot be accessed without a customer ID or account ID. " .
-               "Call save() on \$customer->sources->retrieve('bank_account_id') or " .
-               "\$account->external_accounts->retrieve('bank_account_id') instead.";
+        $msg = "Bank accounts cannot be updated without a customer ID or an " .
+               "account ID. Update a bank account using " .
+               "`Customer::updateSource('customer_id', 'bank_account_id', " .
+               "\$updateParams)` or `Account::updateExternalAccount(" .
+               "'account_id', 'bank_account_id', \$updateParams)`.";
         throw new Error\InvalidRequest($msg, null);
     }
 
diff --git a/lib/Capability.php b/lib/Capability.php
index aabf54b1f..5cb224f9e 100644
--- a/lib/Capability.php
+++ b/lib/Capability.php
@@ -61,8 +61,9 @@ public function instanceUrl()
      */
     public static function retrieve($_id, $_opts = null)
     {
-        $msg = "Capabilities cannot be accessed without an account ID. " .
-               "Retrieve a Capability using \$account->retrieveCapability('acap_123') instead.";
+        $msg = "Capabilities cannot be retrieved without an account ID. " .
+               "Retrieve a capability using `Account::retrieveCapability(" .
+               "'account_id', 'capability_id')`.";
         throw new Error\InvalidRequest($msg, null);
     }
 
@@ -75,8 +76,9 @@ public static function retrieve($_id, $_opts = null)
      */
     public static function update($_id, $_params = null, $_options = null)
     {
-        $msg = "Capabilities cannot be accessed without an account ID. " .
-               "Update a Capability using \$account->updateCapability('acap_123') instead.";
+        $msg = "Capabilities cannot be updated without an account ID. " .
+               "Update a capability using `Account::updateCapability(" .
+               "'account_id', 'capability_id', \$updateParams)`.";
         throw new Error\InvalidRequest($msg, null);
     }
 }
diff --git a/lib/Card.php b/lib/Card.php
index 51eb5add1..98dc70596 100644
--- a/lib/Card.php
+++ b/lib/Card.php
@@ -104,10 +104,10 @@ public function instanceUrl()
      */
     public static function retrieve($_id, $_opts = null)
     {
-        $msg = "Cards cannot be accessed without a customer, recipient or account ID. " .
-               "Retrieve a card using \$customer->sources->retrieve('card_id'), " .
-               "\$recipient->cards->retrieve('card_id'), or " .
-               "\$account->external_accounts->retrieve('card_id') instead.";
+        $msg = "Cards cannot be retrieved without a customer ID or an " .
+               "account ID. Retrieve a card using " .
+               "`Customer::retrieveSource('customer_id', 'card_id')` or " .
+               "`Account::retrieveExternalAccount('account_id', 'card_id')`.";
         throw new Error\InvalidRequest($msg, null);
     }
 
@@ -120,10 +120,11 @@ public static function retrieve($_id, $_opts = null)
      */
     public static function update($_id, $_params = null, $_options = null)
     {
-        $msg = "Cards cannot be accessed without a customer, recipient or account ID. " .
-               "Call save() on \$customer->sources->retrieve('card_id'), " .
-               "\$recipient->cards->retrieve('card_id'), or " .
-               "\$account->external_accounts->retrieve('card_id') instead.";
+        $msg = "Cards cannot be updated without a customer ID or an " .
+               "account ID. Update a card using " .
+               "`Customer::updateSource('customer_id', 'card_id', " .
+               "\$updateParams)` or `Account::updateExternalAccount(" .
+               "'account_id', 'card_id', \$updateParams)`.";
         throw new Error\InvalidRequest($msg, null);
     }
 }
diff --git a/lib/CustomerBalanceTransaction.php b/lib/CustomerBalanceTransaction.php
index 06cafcd45..df1f87902 100644
--- a/lib/CustomerBalanceTransaction.php
+++ b/lib/CustomerBalanceTransaction.php
@@ -67,8 +67,10 @@ public function instanceUrl()
      */
     public static function retrieve($_id, $_opts = null)
     {
-        $msg = "Customer Balance Transactions cannot be accessed without a customer ID. " .
-               "Retrieve a balance transaction using Customer::retrieveBalanceTransaction('cus_123', 'cbtxn_123') instead.";
+        $msg = "Customer Balance Transactions cannot be retrieved without a " .
+               "customer ID. Retrieve a Customer Balance Transaction using " .
+               "`Customer::retrieveBalanceTransaction('customer_id', " .
+               "'balance_transaction_id')`.";
         throw new Error\InvalidRequest($msg, null);
     }
 
@@ -81,8 +83,10 @@ public static function retrieve($_id, $_opts = null)
      */
     public static function update($_id, $_params = null, $_options = null)
     {
-        $msg = "Customer Balance Transactions cannot be accessed without a customer ID. " .
-               "Update a balance transaction using Customer::updateBalanceTransaction('cus_123', 'cbtxn_123', \$params) instead.";
+        $msg = "Customer Balance Transactions cannot be updated without a " .
+               "customer ID. Update a Customer Balance Transaction using " .
+               "`Customer::updateBalanceTransaction('customer_id', " .
+               "'balance_transaction_id', \$updateParams)`.";
         throw new Error\InvalidRequest($msg, null);
     }
 }
diff --git a/lib/Person.php b/lib/Person.php
index 5540f7c5f..52f920a8e 100644
--- a/lib/Person.php
+++ b/lib/Person.php
@@ -86,8 +86,9 @@ public function instanceUrl()
      */
     public static function retrieve($_id, $_opts = null)
     {
-        $msg = "Persons cannot be accessed without an account ID. " .
-               "Retrieve a Person using \$account->retrievePerson('person_id') instead.";
+        $msg = "Persons cannot be retrieved without an account ID. Retrieve " .
+               "a person using `Account::retrievePerson('account_id', " .
+               "'person_id')`.";
         throw new Error\InvalidRequest($msg, null);
     }
 
@@ -100,8 +101,9 @@ public static function retrieve($_id, $_opts = null)
      */
     public static function update($_id, $_params = null, $_options = null)
     {
-        $msg = "Persons cannot be accessed without an account ID. " .
-               "Retrieve a Person using \$account->retrievePerson('person_id') instead.";
+        $msg = "Persons cannot be updated without an account ID. Update " .
+               "a person using `Account::updatePerson('account_id', " .
+               "'person_id', \$updateParams)`.";
         throw new Error\InvalidRequest($msg, null);
     }
 }
diff --git a/lib/TaxId.php b/lib/TaxId.php
index 8d607132e..892954e55 100644
--- a/lib/TaxId.php
+++ b/lib/TaxId.php
@@ -73,8 +73,9 @@ public function instanceUrl()
      */
     public static function retrieve($_id, $_opts = null)
     {
-        $msg = "Tax Ids cannot be accessed without a customer ID. " .
-               "Retrieve a Tax Id using Customer::retrieveTaxId('tax_id') instead.";
+        $msg = "Tax IDs cannot be retrieved without a customer ID. Retrieve " .
+               "a tax ID using `Customer::retrieveTaxId('customer_id', " .
+               "'tax_id_id')`.";
         throw new Error\InvalidRequest($msg, null);
     }
 }