diff --git a/OPENAPI_VERSION b/OPENAPI_VERSION
index 91bb63fb..02b98f78 100644
--- a/OPENAPI_VERSION
+++ b/OPENAPI_VERSION
@@ -1 +1 @@
-v285
\ No newline at end of file
+v291
\ No newline at end of file
diff --git a/lib/stripe/resources/tax/calculation.rb b/lib/stripe/resources/tax/calculation.rb
index 19e00fe0..57f5bc7c 100644
--- a/lib/stripe/resources/tax/calculation.rb
+++ b/lib/stripe/resources/tax/calculation.rb
@@ -3,7 +3,9 @@
 
 module Stripe
   module Tax
-    # A Tax `Calculation` allows you to calculate the tax to collect from your customer.
+    # A Tax Calculation allows you to calculate the tax to collect from your customer.
+    #
+    # Related guide: [Calculate tax in your custom payment flow](https://stripe.com/docs/tax/custom).
     class Calculation < APIResource
       extend Stripe::APIOperations::Create
 
diff --git a/lib/stripe/resources/tax/transaction.rb b/lib/stripe/resources/tax/transaction.rb
index f6c18857..f66864fa 100644
--- a/lib/stripe/resources/tax/transaction.rb
+++ b/lib/stripe/resources/tax/transaction.rb
@@ -3,7 +3,9 @@
 
 module Stripe
   module Tax
-    # A Tax transaction records the tax collected from or refunded to your customer.
+    # A Tax Transaction records the tax collected from or refunded to your customer.
+    #
+    # Related guide: [Calculate tax in your custom payment flow](https://stripe.com/docs/tax/custom#tax-transaction).
     class Transaction < APIResource
       OBJECT_NAME = "tax.transaction"