diff --git a/CHANGELOG.md b/CHANGELOG.md
index 40f55443..59a7cd7e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 * Reverted #64, removing `balance_in_cents_invoiced` and `balance_in_cents_uninvoiced` from `Recurly_Account`. They were never added to the API.
+* Added tax_code to plans, add-ons and adjustments [120](https://github.com/recurly/recurly-client-php/pull/120)
 
 ## Version 2.3.2 (Oct 21st, 2014)
 
diff --git a/Tests/Recurly/Adjustment_Test.php b/Tests/Recurly/Adjustment_Test.php
index 93abb4a8..336a1063 100644
--- a/Tests/Recurly/Adjustment_Test.php
+++ b/Tests/Recurly/Adjustment_Test.php
@@ -68,11 +68,13 @@ public function testXml() {
     $charge->currency = 'USD';
     $charge->quantity = 1;
     $charge->accounting_code = 'bandwidth';
+    $charge->tax_exempt = false;
+    $charge->tax_code = 'fake-tax-code';
 
     // This deprecated parameter should be ignored:
     $charge->taxable = 0;
 
-    $expected = "<?xml version=\"1.0\"?>\n<adjustment><currency>USD</currency><unit_amount_in_cents>5000</unit_amount_in_cents><quantity>1</quantity><description>Charge for extra bandwidth</description><accounting_code>bandwidth</accounting_code></adjustment>\n";
+    $expected = "<?xml version=\"1.0\"?>\n<adjustment><currency>USD</currency><unit_amount_in_cents>5000</unit_amount_in_cents><quantity>1</quantity><description>Charge for extra bandwidth</description><accounting_code>bandwidth</accounting_code><tax_exempt>false</tax_exempt><tax_code>fake-tax-code</tax_code></adjustment>\n";
     $this->assertEquals($expected, $charge->xml());
   }
 }
diff --git a/Tests/Recurly/Plan_Test.php b/Tests/Recurly/Plan_Test.php
index dcb64fe1..4d915859 100644
--- a/Tests/Recurly/Plan_Test.php
+++ b/Tests/Recurly/Plan_Test.php
@@ -62,9 +62,11 @@ public function testUpdateXml() {
     $plan->unit_amount_in_cents->addCurrency('EUR', 1200);
     $plan->setup_fee_in_cents->addCurrency('EUR', 500);
     $plan->total_billing_cycles = NULL;
+    $plan->tax_exempt = false;
+    $plan->tax_code = 'fake-tax-code';
 
     $this->assertEquals(
-      "<?xml version=\"1.0\"?>\n<plan><plan_code>platinum</plan_code><name>Platinum Plan</name><unit_amount_in_cents><USD>1500</USD><EUR>1200</EUR></unit_amount_in_cents><setup_fee_in_cents><USD>500</USD><EUR>500</EUR></setup_fee_in_cents><total_billing_cycles nil=\"nil\"></total_billing_cycles></plan>\n",
+      "<?xml version=\"1.0\"?>\n<plan><plan_code>platinum</plan_code><name>Platinum Plan</name><unit_amount_in_cents><USD>1500</USD><EUR>1200</EUR></unit_amount_in_cents><setup_fee_in_cents><USD>500</USD><EUR>500</EUR></setup_fee_in_cents><total_billing_cycles nil=\"nil\"></total_billing_cycles><tax_exempt>false</tax_exempt><tax_code>fake-tax-code</tax_code></plan>\n",
       $plan->xml()
     );
   }
diff --git a/lib/recurly/addon.php b/lib/recurly/addon.php
index d5558d46..d97b6f0e 100644
--- a/lib/recurly/addon.php
+++ b/lib/recurly/addon.php
@@ -14,7 +14,7 @@ public static function init()
   {
     Recurly_Addon::$_writeableAttributes = array(
       'add_on_code','name','display_quantity','default_quantity',
-      'unit_amount_in_cents','accounting_code'
+      'unit_amount_in_cents','accounting_code','tax_code'
     );
     Recurly_Addon::$_nestedAttributes = array();
   }
diff --git a/lib/recurly/adjustment.php b/lib/recurly/adjustment.php
index a68ff024..0b96225e 100644
--- a/lib/recurly/adjustment.php
+++ b/lib/recurly/adjustment.php
@@ -9,7 +9,7 @@ public static function init()
   {
     Recurly_Adjustment::$_writeableAttributes = array(
       'currency','unit_amount_in_cents','quantity','description',
-      'accounting_code','tax_exempt'
+      'accounting_code','tax_exempt','tax_code'
     );
     Recurly_Adjustment::$_nestedAttributes = array(
       'invoice'
diff --git a/lib/recurly/plan.php b/lib/recurly/plan.php
index ea68e68e..b6611a04 100644
--- a/lib/recurly/plan.php
+++ b/lib/recurly/plan.php
@@ -19,7 +19,7 @@ public static function init()
       'bypass_hosted_confirmation','unit_name','payment_page_tos_link',
       'plan_interval_length','plan_interval_unit','trial_interval_length',
       'trial_interval_unit','unit_amount_in_cents','setup_fee_in_cents',
-      'total_billing_cycles','accounting_code','tax_exempt'
+      'total_billing_cycles','accounting_code','tax_exempt','tax_code'
     );
     Recurly_Plan::$_nestedAttributes = array(
       'add_ons'