diff --git a/src/app/Observers/EntitlementObserver.php b/src/app/Observers/EntitlementObserver.php
--- a/src/app/Observers/EntitlementObserver.php
+++ b/src/app/Observers/EntitlementObserver.php
@@ -88,4 +88,55 @@
         $entitlement->entitleable->updated_at = Carbon::now();
         $entitlement->entitleable->save();
     }
+
+    public function deleting(Entitlement $entitlement)
+    {
+        // Start calculating the costs for the consumption of this entitlement if the
+        // existing consumption spans >= 14 days.
+        // anything's free for 14 days
+        if ($entitlement->created_at >= Carbon::now()->subDays(14)) {
+            return;
+        }
+
+        $cost = 0;
+
+        // get the discount rate applied to the wallet.
+        $discount = $entitlement->wallet->getDiscountRate();
+
+        // just in case this had not been billed yet, ever
+        $diffInMonths = $entitlement->updated_at->diffInMonths(Carbon::now());
+        $cost += (int) ($entitlement->cost * $discount * $diffInMonths);
+
+        // this moves the hypothetical updated at forward to however many months past the original
+        $updatedAt = $entitlement->updated_at->copy()->addMonthsWithoutOverflow($diffInMonths);
+
+        // now we have the diff in days since the last "billed" period end.
+        // This may be an entitlement paid up until February 28th, 2020, with today being March
+        // 12th 2020. Calculating the costs for the entitlement is based on the daily price for the
+        // past month -- i.e. $price/29 in the case at hand -- times the number of (full) days in
+        // between the period end and now.
+        //
+        // a) The number of days left in the past month, 1
+        // b) The cost divided by the number of days in the past month, for example, 555/29,
+        // c) a) + Todays day-of-month, 12, so 13.
+        //
+
+        $diffInDays = $updatedAt->diffInDays(Carbon::now());
+
+        $dayOfThisMonth = Carbon::now()->day;
+
+        // days in the month for the month prior to this one.
+        // the price per day is based on the number of days left in the last month
+        $daysInLastMonth = \App\Utils::daysInLastMonth();
+
+        $pricePerDay = (float)$entitlement->cost / $daysInLastMonth;
+
+        $cost += (int) (round($pricePerDay * $diffInDays, 0));
+
+        if ($cost == 0) {
+            return;
+        }
+
+        $entitlement->wallet->debit($cost);
+    }
 }
diff --git a/src/tests/Feature/EntitlementTest.php b/src/tests/Feature/EntitlementTest.php
--- a/src/tests/Feature/EntitlementTest.php
+++ b/src/tests/Feature/EntitlementTest.php
@@ -37,11 +37,11 @@
      */
     public function testUserAddEntitlement(): void
     {
-        $package_domain = Package::where('title', 'domain-hosting')->first();
-        $package_kolab = Package::where('title', 'kolab')->first();
+        $packageDomain = Package::where('title', 'domain-hosting')->first();
+        $packageKolab = Package::where('title', 'kolab')->first();
 
-        $sku_domain = Sku::where('title', 'domain-hosting')->first();
-        $sku_mailbox = Sku::where('title', 'mailbox')->first();
+        $skuDomain = Sku::where('title', 'domain-hosting')->first();
+        $skuMailbox = Sku::where('title', 'mailbox')->first();
 
         $owner = $this->getTestUser('entitlement-test@kolabnow.com');
         $user = $this->getTestUser('entitled-user@custom-domain.com');
@@ -54,19 +54,22 @@
             ]
         );
 
-        $domain->assignPackage($package_domain, $owner);
+        $domain->assignPackage($packageDomain, $owner);
 
-        $owner->assignPackage($package_kolab);
-        $owner->assignPackage($package_kolab, $user);
+        $owner->assignPackage($packageKolab);
+        $owner->assignPackage($packageKolab, $user);
 
         $wallet = $owner->wallets->first();
 
         $this->assertCount(4, $owner->entitlements()->get());
-        $this->assertCount(1, $sku_domain->entitlements()->where('wallet_id', $wallet->id)->get());
-        $this->assertCount(2, $sku_mailbox->entitlements()->where('wallet_id', $wallet->id)->get());
+        $this->assertCount(1, $skuDomain->entitlements()->where('wallet_id', $wallet->id)->get());
+        $this->assertCount(2, $skuMailbox->entitlements()->where('wallet_id', $wallet->id)->get());
         $this->assertCount(9, $wallet->entitlements);
 
-        $this->backdateEntitlements($owner->entitlements, Carbon::now()->subMonthsWithoutOverflow(1));
+        $this->backdateEntitlements(
+            $owner->entitlements,
+            Carbon::now()->subMonthsWithoutOverflow(1)
+        );
 
         $wallet->chargeEntitlements();
 
@@ -92,17 +95,51 @@
         $sku = \App\Sku::where('title', 'mailbox')->first();
         $this->assertNotNull($sku);
 
-        $entitlement = Entitlement::where('wallet_id', $wallet->id)->where('sku_id', $sku->id)->first();
+        $entitlement = Entitlement::where('wallet_id', $wallet->id)
+            ->where('sku_id', $sku->id)->first();
+
         $this->assertNotNull($entitlement);
 
-        $e_sku = $entitlement->sku;
-        $this->assertSame($sku->id, $e_sku->id);
+        $eSKU = $entitlement->sku;
+        $this->assertSame($sku->id, $eSKU->id);
+
+        $eWallet = $entitlement->wallet;
+        $this->assertSame($wallet->id, $eWallet->id);
+
+        $eEntitleable = $entitlement->entitleable;
+        $this->assertEquals($user->id, $eEntitleable->id);
+        $this->assertTrue($eEntitleable instanceof \App\User);
+    }
+
+    public function testBillDeletedEntitlement(): void
+    {
+        $user = $this->getTestUser('entitlement-test@kolabnow.com');
+        $package = \App\Package::where('title', 'kolab')->first();
+
+        $storage = \App\Sku::where('title', 'storage')->first();
+
+        $user->assignPackage($package);
+        // some additional SKUs so we have something to delete.
+        $user->assignSku($storage, 4);
+
+        $wallet = $user->wallets()->first();
+
+        $this->backdateEntitlements($user->entitlements, Carbon::now()->subWeeks(7));
+
+        $charge = $wallet->chargeEntitlements();
+
+        $this->assertTrue($wallet->balance < 0);
+
+        $balance = $wallet->balance;
 
-        $e_wallet = $entitlement->wallet;
-        $this->assertSame($wallet->id, $e_wallet->id);
+        // the delta between updated_at and now should be ~3 weeks. this opens it up for deletion.
+        foreach ($user->entitlements as $entitlement) {
+            if ($entitlement->sku_id == $storage->id && $entitlement->cost > 0) {
+                $entitlement->delete();
+            }
+        }
 
-        $e_entitleable = $entitlement->entitleable;
-        $this->assertEquals($user->id, $e_entitleable->id);
-        $this->assertTrue($e_entitleable instanceof \App\User);
+        // we expect the wallet to have been charged.
+        $this->assertTrue($wallet->fresh()->balance < $balance);
     }
 }