Google Drive storage plan purchases are non-refundable. The amount of storage you purchased is yours for the length of the subscription regardless of if you decide to cancel at any point.
By default, your storage purchase is set to automatically renew at the end of your subscription. At any point during your subscription, you can upgrade to a larger storage plan. You'll be upgraded to your new storage level immediately, and your credit card will be charged when you run out of credit.
If you purchased a storage subscription under the old pricing plan, you can renew your subscription until you choose to upgrade or until your payment information expires.
About cancellation and expiration
When you cancel your storage plan or when your storage plan expires, your storage limits will be set back to the free levels for each product at the end of your billing cycle. Everything in Google Drive, G+ Photos and Gmail will still be accessible, but you won't be able to create or add anything new over the free storage limit.
- Google Drive and Google+ Photos (5 GB free storage): If you've reached or exceeded the free storage limit, you won't be able to sync or upload any new files, and syncing between your Google Drive folder and My Drive stops completely. You'll still be able to create Google Docs, since they don't take up any storage space. For G+ Photos, you will only be able to upload new photos and videos under certain size limits.
- Gmail (10 GB free storage): If you cancel your Google Drive storage plan, you'll be downgraded to 10 GB free storage in Gmail. If you're over that limit, incoming messages to your account will be returned to the sender.
Cancel your subscription
You can cancel the your storage subscription at any point.
- Go to https://www.google.com/settings/storage .
- Sign into the Google Account for which you purchased storage.
- Your account will show in the left-hand box. Click Downgrade account.
- Select "Downgrade" next to the 5 GB free version.
- Review your choice and click Continue to Wallet.
- Click Finish to cancel your subscription. You'll receive a confirmation email.
- On the start of the next month of your plan, you'll be downgraded to the free storage levels for Google Drive and G+ Photos, and Gmail.