How to Stop Spam Texts on Android: Let Only Contacts Through

Stop spam texts with Google Messages

If your phone uses Google Messages, start with its own tools:

• Spam and scam protection: Google says that when Google Messages detects suspected spam or scams, it can prevent those messages from being delivered and hide them in the Spam & blocked folder. To check the setting, tap your profile picture or initials, then Messages settings → Protection & Safety → Spam and scam protection. See Google’s spam and scam protection help.
• Block a sender: on the home screen of Google Messages, touch and hold the conversation, then tap Block and OK. See Google’s block and report help.

Blocking works one sender at a time, so it doesn’t help much when every new spam text comes from a different number. That’s when a contacts-only rule is simpler.

Let only your contacts text you with BIG SMS

BIG SMS is an easy-to-use SMS app with large text for easier reading, and it works on almost any Android phone (Android 6.0 or newer). Its Incoming SMS filter can ignore every new text from a number that isn’t in your Contacts. The filter is in the free version.

1. Install BIG SMS from Google Play and open it.
2. When BIG SMS asks to become your default SMS app, tap Yes. Only the default SMS app can send and receive messages.
3. Tap Preferences in BIG SMS’s menu (the first item), then tap Messages. If you open BIG SMS from BIG Launcher, this item isn’t there; see the BIG Launcher note below.

4. Scroll down to the Incoming SMS filter section and tap Block numbers:.
5. Choose Which are not in Contacts.

What happens when a spam text arrives

We tried it on our own test phone. Emma is saved in Contacts; the two other numbers aren’t.

Before: with Block numbers: set to None, a prize text from an unknown number arrived and appeared at the top of BIG SMS under New messages.

After: with Which are not in Contacts on, the same prize text from another unknown number never showed up. BIG SMS didn’t save it. A new text from Emma arrived as usual.

The rule works on new texts. Messages that arrived before you switched it on stay in the list.

Before you switch it on: save the numbers that matter

The rule is strict. A text from any number that isn’t in your Contacts is stopped, including a sign-in code, a delivery notice or a pharmacy reminder sent from a number you haven’t saved. Our manual puts it plainly: strong filters can hide important messages.

• Save the numbers you need texts from: family, doctors, the pharmacy and anyone who helps you.
• Waiting for a code or a notice from a new number? Set Block numbers: back to None until it arrives, then switch the rule on again.
• Want only a few people to reach you? Which are not Starred lets through only texts from your starred contacts. It’s even stricter, so star everyone important first.
• Want to stop just a few senders and keep everything else? Leave Block numbers: on None and add those numbers to the Blocked numbers list, which always rejects messages from the numbers in it.

What this setting doesn’t do

• It decides by sender, not by what the text says. A text from a saved contact still comes through.
• It works on SMS text messages in BIG SMS. It doesn’t filter WhatsApp or other chat apps.
• It isn’t scam protection. It simply keeps texts from numbers you haven’t saved out of your list.
• It doesn’t delete texts that arrived before you switched it on.

BIG SMS is part of the BIG Apps family

The family’s main app, and our flagship, is BIG Launcher: a simple home screen with large buttons, where the Messages button opens BIG SMS and the Phone button opens BIG Phone. BIG Launcher has 4.3 ★ on Google Play from 8,000+ reviews and more than 2 million downloads, and it’s available in 70 languages. Get BIG Launcher on Google Play.

With BIG Apps Suite PREMIUM, you get BIG Launcher, BIG Phone, BIG SMS and BIG Notifications for one price. You buy it in BIG Launcher. New BIG Apps Suite PREMIUM customers get a 7-day yearly trial. See the plans and free-version limits.

If BIG Launcher is on the phone too: BIG Launcher has the same Block numbers setting under the three dots next to the clock → Preferences → Messages. When you open BIG SMS from BIG Launcher, it takes over BIG Launcher’s settings and shows no Preferences item, and a change made only in BIG SMS can be overwritten. So make the change in BIG Launcher, then open BIG SMS from BIG Launcher once.

Unknown numbers calling, too? See how to block unknown callers on Android with BIG Phone. For bigger text when you read and answer texts, see reading and replying to SMS with larger text.

Frequently asked questions

How do I stop spam texts on Android?

Turn on spam protection in your messaging app and block senders you don’t want. If spam keeps coming from new numbers, use BIG SMS with Block numbers: set to Which are not in Contacts under Preferences → Messages → Incoming SMS filter. New texts from numbers that aren’t in your Contacts then don’t reach your message list.

How do I block texts from unknown numbers on Android?

In Google Messages you can block one conversation at a time: touch and hold it, then tap Block. To stop texts from every number you haven’t saved, make BIG SMS your default SMS app and choose Which are not in Contacts under Block numbers:.

Will I still get verification codes?

Not if the code comes from a number that isn’t in your Contacts. Save that number, or set Block numbers: back to None while you wait for the code.

Does the filter delete spam I already have?

No. It works on new texts. On our test phone, a spam text that arrived before we switched the rule on stayed in the list.

Is BIG SMS free?

Yes. The free version has no time limit and includes the Incoming SMS filter. It shows only the 5 most recent message threads, and after 20 sent texts it adds a link to biglauncher.com to every text you send; the full version removes these limits.