Guides · Contacts

Keeping your address book private: a practical checklist

Updated 12 October 2026 · 7 min read

When we think about privacy, we usually think about our own data: our messages, our photos, our location. An address book is different. Almost nothing in it is about you. It holds other people's names, phone numbers, home addresses, birthdays and e-mail addresses, along with whatever notes you've added about them. None of those people chose where their details are stored, or who else might be able to read them.

That's a good reason to look after it carefully. The checklist below covers the habits that matter most. Most of it applies whatever address book you use.

1. Be careful which apps you let read your contacts

Many apps ask for access to your contacts. Messaging apps, social networks, games, shopping apps and photo editors all do it. Sometimes there's a clear reason: a messaging app wants to show which of your friends already use it. But once an app has access, it can usually read the whole list, and depending on its privacy policy it may copy the list to its own servers. Your friends end up in a database they never signed up for.

Before you tap Allow, ask yourself two questions:

  • Does this app actually need my contacts to do what I want from it?
  • Could I just type in or pick the one person I need instead?

If the answer isn't clearly yes, say no. You can almost always grant access later if you change your mind.

2. Review which apps already have access

Most of us said yes to some of these requests years ago and have forgotten. It takes a few minutes to check.

On Android

Open the Settings app and go to Security and privacy › Privacy › Permission manager, then tap Contacts. This lists every app that can read your contacts. Tap an app and choose Don't allow if it doesn't need access. You can also go app by app under Settings › Apps › (the app) › Permissions. Menu names differ between phone makers and Android versions, so if you can't find these menus, search for "permission" in the Settings app. Google's steps are in its help page on changing app permissions.

On iPhone and iPad

Open Settings › Privacy & Security › Contacts to see every app that has asked for access, and change each one. Recent versions of iOS also let you give an app access to only the contacts you pick, rather than the whole list, which is a good middle ground for apps that only need a few. Apple explains this in Control access to information in apps on iPhone.

Tip: Put a reminder in your calendar to check these permissions once or twice a year. New apps pile up quickly.

3. Don't store what doesn't belong in an address book

The notes field is very handy, and it's easy to let it turn into a junk drawer. Some things should never go in it:

  • Passwords, PINs and door codes. This includes your own Wi-Fi password and the key-safe code for an elderly relative's house. Use a password manager for these.
  • Identity and financial numbers: passport, national insurance or social security numbers, bank details, card numbers. If someone gets into your address book, these are what make identity theft easy.
  • Health information, or anything you'd be uncomfortable with the person reading. A good test: would you be happy if they saw what you wrote about them?

Name, ways to get in touch, address, birthday and a few practical notes ("prefers texts", "met at the 2025 conference") are all an address book needs.

4. Share one contact on purpose, not everything by default

When someone asks for a friend's details, you don't need to sync or share your whole address book. Send just that one contact as a vCard (.vcf) file. Any phone or contacts app can open it.

  • Check what's in the card first. Sharing a contact usually sends everything on it, notes included. Remove anything private before you send it.
  • Ask first if you're passing on someone's mobile number or home address. It's polite, and it's their information.
  • Be wary of "find friends" and sync features that upload your whole list to a service so it can match people. That isn't the same as sharing one person deliberately.

In TheyreMine, open a contact and click Export vCard to download a file for that one person, ready to attach to an e-mail. See exporting a contact. Nothing else in your address book goes with it.

5. Know what your address book provider does with the data

Wherever your contacts are stored, it's worth reading the privacy policy for the answers to three questions. Is the data used for advertising? Is it shared with other companies? Can you get it out and delete it?

TheyreMine's privacy policy answers these. Contacts are private to your account and never visible to other users. Contact data is never used for advertising or analytics profiling, and it isn't shared with third parties, including the site's analytics and advertising services. When you import a vCard or CSV file, the file is processed to create your contacts and isn't kept afterwards.

6. Protect the account itself

Most of this privacy depends on one thing: nobody else can sign in as you.

  • Use a strong, unique password. A long passphrase of several unrelated words is easier to remember and harder to guess than a short, complicated one. Above all, don't reuse a password from another site. When one site is breached, attackers try the same e-mail and password everywhere else.
  • Use a password manager so you don't have to remember dozens of unique passwords.
  • Log out on shared or public computers. In TheyreMine, use the Logout link at the top of the page. Then close the browser, and don't let it save your password.
  • Change your password straight away if you think someone else might know it.
  • Keep your e-mail account secure, ideally with two-step verification. Password resets go to your e-mail, so whoever controls it can usually get into everything else.

7. Keep backups, and keep them private

Losing an address book is miserable, so keep a copy. But a backup is a full copy of everyone's details, which makes it worth protecting too.

  • Export your contacts every so often. vCard is the most widely readable format.
  • Keep the file on an encrypted drive, or in a cloud folder protected by a strong password, not loose in your Downloads folder.
  • Delete old backups and stray export files once you have a newer one. Every leftover copy is one more thing that could leak.

TheyreMine exports contacts one at a time as vCards, which is handy for keeping copies of your most important entries. If you moved your contacts in from Google, iCloud or Outlook, keep the original export file somewhere safe as well.

8. Delete what you no longer need

The safest data is data you no longer hold. Once a year, scroll through your contacts and delete:

  • people you'll never contact again, such as old landlords, one-off tradespeople or former colleagues;
  • numbers and addresses you know are out of date;
  • notes that are no longer relevant, or that you'd rather not have written.

In TheyreMine, deleting a contact also removes all of their e-mail addresses and phone numbers, and it can't be undone. See deleting contacts. If you decide to leave altogether, the privacy policy explains how to ask for your account and all of its data to be deleted.

The checklist

  1. Only let apps read your contacts when they genuinely need to.
  2. Review contact permissions on your phone once or twice a year.
  3. Keep passwords, ID numbers, financial details and health information out of your address book.
  4. Share one contact as a vCard instead of syncing your whole list, and check what's on the card first.
  5. Read your provider's privacy policy on advertising and sharing.
  6. Use a strong, unique password and log out on shared computers.
  7. Keep a private, up-to-date backup and delete old copies.
  8. Delete contacts and notes you no longer need.

None of this takes long, and the people in your address book benefit from every step, even though they'll never know you took it.