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How to block spam calls and texts on your business number

Onyx Phone lets you block spam callers, robocalls, and unwanted texts so they never ring your team. Block a number on every line or just one, block only calls or only texts, choose what a blocked caller hears, and block callers who hide their caller ID. This guide shows each way to block a number on the web and in the iPhone and Android apps, and how to unblock it.

Web appAndroid appiPhone app Updated November 6, 2026

Step 1. Block a number from a call or voicemail Web app

  1. Step 1.a Open the call from Calls.
  2. Step 1.b Click Block caller at the top of the page.
  3. Step 1.c Choose where to block it, Only on this line or On all lines.
  4. Step 1.d Choose a reason in Why, such as Spam calls.
  5. Step 1.e Click the red Block caller button. The number can no longer call or text that line.
The Block caller menu open on a call's page, with the line choice, the reason, and the red Block caller button highlighted.
Block caller (1.b), where to block (1.c), why (1.d), and confirm (1.e).

Step 2. Block a number on the Blocked numbers page Web app

  1. Step 2.a Click your initials at the top right of the screen, then click Blocked numbers.
  2. Step 2.b In Number, type the number to block. Leave it empty to block callers who hide their caller ID.
  3. Step 2.c In Where, choose All lines or one line.
  4. Step 2.d In Block, choose Calls and texts, Calls only, or Texts only. Nothing (an exception to a wider block) lets one line keep taking a number you block everywhere else.
  5. Step 2.e In What a blocked caller hears, choose a rejection message, a busy signal, or a short message before hanging up.
  6. Step 2.f Optionally add a Note so your team knows why, then click Block number.
The Blocked numbers page with the Block a number form, showing Number, Where, Block, What a blocked caller hears, Note, and the Block number button.
The account menu's Blocked numbers page, with each field labeled by its step.

Step 3. Change or remove a block Web app

  1. Step 3.a On Blocked numbers, find the number under Blocked. Each row shows where it's blocked, what's blocked, and how many calls and texts it has stopped.
  2. Step 3.b Click Edit to change where or what it blocks, then save.
  3. Step 3.c Click Unblock, then OK, to let the number reach you again.
The list of blocked numbers with where each is blocked and the Edit and Unblock buttons highlighted.
The Blocked list (3.a), Edit (3.b), and Unblock (3.c).

Step 4. Block a number in the iPhone or Android app iPhone and Android

  1. Step 4.a Tap the ⋮ Settings button at the top right of the app, then tap Blocked numbers.
  2. Step 4.b Tap the + button at the top right.
  3. Step 4.c Type the number in Phone number. Leave it empty to block hidden caller ID.
  4. Step 4.d Under Where, tap All lines or one line.
  5. Step 4.e Under Block, tap Calls and texts, Calls only, Texts only, or Exception.
  6. Step 4.f Choose what a blocked caller hears, then tap Block.
  7. Step 4.g To change or remove a block, tap it in the list.

Tip: In a text conversation in the app, tap the block button at the top of the screen to block that number in one step.

The Blocked numbers screen in the Onyx Phone app, listing blocked numbers with what each blocks, and the add button highlighted.
The add button (4.b) and a blocked number (4.g).
The Block a number window in the Onyx Phone app with the phone number, Where, Block, and what callers hear, and the Block button.
The number (4.c), where (4.d), what to block (4.e), and Block (4.f).

Questions and answers

What does a blocked caller hear?

You choose. Reject tells them the number is not available, Busy signal plays a busy tone, or Onyx Phone can say the number doesn't take their calls and hang up. Nobody on your team's phones rings either way.

Can I block callers with no caller ID?

Yes. Leave the number empty when you add a block and it applies to callers who hide their number (shown as Hidden caller ID).

Do blocked texts still arrive?

No. Texts from a number blocked for texts never reach Messages. Block Calls only if you still want their texts.

Who can block numbers?

Account admins can block on any line. Teammates can block on their own lines when an admin allows it on the teammate's page in Team, under Permissions.

How is blocking different from the robocall filter?

Blocking stops specific numbers you choose. The robocall filter asks every caller on a line to press 1 before it rings, which stops automated calls from numbers you haven't seen yet. See Phone menu and call routing.

Can I see how often a blocked number tried to reach us?

Yes. Each blocked number shows how many calls and texts it has stopped, on the website and in the apps.

Getting started

  1. Create a login and pick a plan. Checkout saves a card for the 7-day free trial, and nothing is charged until it ends.
  2. Confirm your business and its 911 address, and get a local number on the spot. Bringing your own number? You answer on a temporary one while it moves over, for free.
  3. Choose where calls ring, write what callers hear, invite your team, and register for texting. Then answer in the browser, the iPhone and Android apps, or a desk phone. How it works has the details.

Screens change as we improve Onyx Phone; we last checked this guide on November 6, 2026. The screenshots show a made-up business. Markdown version · All guides · Contact us