diff --git a/lib/checkout_sdk/payments/sessions/payment_methods_type.rb b/lib/checkout_sdk/payments/sessions/payment_methods_type.rb
index 7209098..6717c08 100644
--- a/lib/checkout_sdk/payments/sessions/payment_methods_type.rb
+++ b/lib/checkout_sdk/payments/sessions/payment_methods_type.rb
@@ -2,19 +2,55 @@
 
 module CheckoutSdk
   module Payments
+    # The type of payment method that can be enabled or disabled for a payment session.
+    #
+    # This is a consolidated list covering every payment method the Flow API accepts for
+    # enabled_payment_methods / disabled_payment_methods. Constants marked deprecated are no
+    # longer part of the specification but are kept for backward compatibility.
     module PaymentMethodsType
+      ALIPAY_CN = 'alipay_cn'
+      ALIPAY_HK = 'alipay_hk'
+      ALMA = 'alma'
       APPLEPAY = 'applepay'
       BANCONTACT = 'bancontact'
+      BENEFIT = 'benefit'
+      BIZUM = 'bizum'
       CARD = 'card'
+      DANA = 'dana'
       EPS = 'eps'
+      # @deprecated No longer part of the specification.
       GIROPAY = 'giropay'
+      GCASH = 'gcash'
       GOOGLEPAY = 'googlepay'
       IDEAL = 'ideal'
+      KAKAOPAY = 'kakaopay'
+      KLARNA = 'klarna'
       KNET = 'knet'
+      MBWAY = 'mbway'
+      MOBILEPAY = 'mobilepay'
       MULTIBANCO = 'multibanco'
+      OCTOPUS = 'octopus'
       PRZELEWY24 = 'p24'
+      PAYNOW = 'paynow'
       PAYPAL = 'paypal'
+      PLAID = 'plaid'
+      QPAY = 'qpay'
+      # Fully supported by the API but deliberately unlisted in the public specification, so
+      # that merchants do not disable Remember Me en masse. Do not remove it as an unspecified
+      # value.
+      REMEMBER_ME = 'remember_me'
+      SEPA = 'sepa'
+      # @deprecated No longer part of the specification.
       SOFORT = 'sofort'
+      STCPAY = 'stcpay'
+      STORED_CARD = 'stored_card'
+      TABBY = 'tabby'
+      TAMARA = 'tamara'
+      TNG = 'tng'
+      TRUEMONEY = 'truemoney'
+      TWINT = 'twint'
+      VIPPS = 'vipps'
+      WECHATPAY = 'wechatpay'
     end
   end
 end