diff --git a/src/applications/phortune/storage/PhortuneSubscription.php b/src/applications/phortune/storage/PhortuneSubscription.php
--- a/src/applications/phortune/storage/PhortuneSubscription.php
+++ b/src/applications/phortune/storage/PhortuneSubscription.php
@@ -207,6 +207,13 @@
       $end_epoch);
   }
 
+  public function shouldInvoiceForBillingPeriod($start_epoch, $end_epoch) {
+    return $this->getImplementation()->shouldInvoiceForBillingPeriod(
+      $this,
+      $start_epoch,
+      $end_epoch);
+  }
+
   public function getPurchaseName(
     PhortuneProduct $product,
     PhortunePurchase $purchase) {
diff --git a/src/applications/phortune/subscription/PhortuneSubscriptionImplementation.php b/src/applications/phortune/subscription/PhortuneSubscriptionImplementation.php
--- a/src/applications/phortune/subscription/PhortuneSubscriptionImplementation.php
+++ b/src/applications/phortune/subscription/PhortuneSubscriptionImplementation.php
@@ -22,6 +22,13 @@
     $start_epoch,
     $end_epoch);
 
+  public function shouldInvoiceForBillingPeriod(
+    PhortuneSubscription $subscription,
+    $start_epoch,
+    $end_epoch) {
+    return true;
+  }
+
   public function getCartName(
     PhortuneSubscription $subscription,
     PhortuneCart $cart) {
diff --git a/src/applications/phortune/worker/PhortuneSubscriptionWorker.php b/src/applications/phortune/worker/PhortuneSubscriptionWorker.php
--- a/src/applications/phortune/worker/PhortuneSubscriptionWorker.php
+++ b/src/applications/phortune/worker/PhortuneSubscriptionWorker.php
@@ -8,6 +8,13 @@
     $range = $this->getBillingPeriodRange($subscription);
     list($last_epoch, $next_epoch) = $range;
 
+    $should_invoice = $subscription->shouldInvoiceForBillingPeriod(
+      $last_epoch,
+      $next_epoch);
+    if (!$should_invoice) {
+      return;
+    }
+
     $account = $subscription->getAccount();
     $merchant = $subscription->getMerchant();
 
@@ -21,7 +28,6 @@
     $cart_implementation = id(new PhortuneSubscriptionCart())
       ->setSubscription($subscription);
 
-
     // TODO: This isn't really ideal. It would be better to use an application
     // actor than the original author of the subscription. In particular, if
     // someone initiates a subscription, adds some other account managers, and