How Google Voice works
Google Voice stores, processes and maintains your call history (including calling party phone number, called party phone number, date, time and duration of call), voicemail greeting(s), voicemail messages, Short Message Service (SMS) messages, recorded conversations and other data related to your account in order to provide the service to you.
You may organise or delete your call history, voicemail greeting(s), voicemail messages (both audio and/or transcriptions), Short Message Service (SMS) messages and recorded conversations through your Google Voice account. Such deletions will take immediate effect in your account view, except that your inbox and call history for billable calls will remain visible on your account. Residual copies of deleted data and accounts, except call record information, may take up to 90 days to be deleted from our active servers and may remain in our backup systems. Anonymised copies of call record information, with no personally identifiable information, will be retained in our systems to meet our reporting and auditing requirements.