diff --git a/expiring_stripe_cc.ipynb b/expiring_stripe_cc.ipynb
new file mode 100644
index 00000000..55215873
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+++ b/expiring_stripe_cc.ipynb
@@ -0,0 +1,167 @@
+{
+ "metadata": {
+  "name": "expiring_stripe_cc"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "# working out logic around expiring credit cards"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from regluit.payment.stripelib import StripeClient\n",
+      "from regluit.payment.models import Account\n",
+      "\n",
+      "from django.db.models import Q, F\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from regluit.payment.models import Account\n",
+      "from django.db.models import Q\n",
+      "\n",
+      "month = 7\n",
+      "year = 2013\n",
+      "\n",
+      "# look only at active accounts\n",
+      "\n",
+      "active_accounts = Account.objects.filter(Q(date_deactivated__isnull=True))\n",
+      "\n",
+      "# calculate expired cards\n",
+      "accounts_expired = active_accounts.filter((Q(card_exp_year__lt=year) | Q(card_exp_year=year, card_exp_month__lt = month)))\n",
+      "\n",
+      "# expiring on a given month\n",
+      "\n",
+      "accounts_expiring = active_accounts.filter(card_exp_year=year, card_exp_month = month)\n",
+      "\n",
+      "# yet to expire\n",
+      "\n",
+      "accounts_expiring_later = active_accounts.filter((Q(card_exp_year__gt=year) | Q(card_exp_year=year, card_exp_month__gt = month)))\n",
+      "\n",
+      "print active_accounts.count()\n",
+      "print accounts_expired.count(), accounts_expiring.count(), accounts_expiring_later.count()\n",
+      "\n",
+      "[(account.card_exp_month, account.card_exp_year) for account in accounts_expired]"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "# validity of accounts"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from regluit.payment.stripelib import StripeClient\n",
+      "from django.db.models import Q\n",
+      "\n",
+      "sc = StripeClient()\n",
+      "customers = list(sc._all_objs('Customer'))\n",
+      "\n",
+      "[(customer.active_card[\"address_line1_check\"], \n",
+      "customer.active_card[\"address_zip_check\"], \n",
+      "customer.active_card[\"cvc_check\"]) for customer in customers]\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "[(customer.active_card[\"address_line1_check\"], \n",
+      "customer.active_card[\"address_zip_check\"], \n",
+      "customer.active_card[\"cvc_check\"]) for customer in customers]"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "# look at only customers that are attached to active Account"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from regluit.payment.stripelib import StripeClient\n",
+      "from regluit.payment.models import Account\n",
+      "\n",
+      "sc = StripeClient()\n",
+      "customers = sc._all_objs('Customer')\n",
+      "\n",
+      "active_accounts = Account.objects.filter(Q(date_deactivated__isnull=True))\n",
+      "\n",
+      "active_customer_ids = set([account.account_id for account in active_accounts])\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "[(customer.active_card[\"address_line1_check\"], \n",
+      "customer.active_card[\"address_zip_check\"], \n",
+      "customer.active_card[\"cvc_check\"]) for customer in customers if customer.id in active_customer_ids]"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "# should we delete stripe accounts associated with deactivated accounts -- I think yes"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "len(active_customer_ids)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
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