How to block numbers and filter calls in Zendesk Talk

Unwanted calls are a persistent headache for support teams. Whether it's spam, harassment, or simply wrong numbers tying up your agents, every minute spent on an irrelevant call is a minute not spent helping real customers. If you are using Zendesk Talk, you have built-in tools to manage this problem, though they come with some important limitations you should understand upfront.

This guide walks you through everything you need to know about blocking numbers and filtering calls in Zendesk Talk. We'll cover the native blocking features, workarounds for trickier scenarios like anonymous callers, and alternative approaches when Zendesk's capabilities fall short.

Understanding Zendesk Talk's call blocking capabilities

Zendesk Talk is the native voice solution built into the Zendesk platform. It positions itself as an AI-powered voice support system with end-to-end coverage across the entire call journey. The call blocking feature is one component of this broader phone system.

Here's what you can do natively:

However, there are significant limitations. Most importantly, Zendesk Talk cannot block truly anonymous or "unknown" callers. If someone hides their caller ID, the system has no number to evaluate against your block list. This is a common frustration for support teams dealing with persistent harassment or spam from hidden numbers.

Another constraint is plan availability. Call blocking requires Talk Professional or Enterprise. If you're on Talk Team, this feature is not available. You'll need to upgrade to access blocking capabilities.

How to block specific numbers in Zendesk Talk

Blocking a number in Zendesk Talk is straightforward once you know where to look. Here's the step-by-step process.

Step 1: Access the blocked numbers settings

Navigate to Admin Center > Channels > Talk > Blocked numbers. This section is only visible if your plan supports call blocking.

Step 2: Add a number to the block list

Click "Add number" and enter the specific phone number you want to block. You must use E.164 international format, which includes the plus sign and country code. For example, a US number would look like +12055752345.

Step 3: Configure blocking conditions

You have three condition options:

• Equal to — Blocks exactly this number
• Starts with — Blocks any number beginning with these digits (useful for blocking area codes or country prefixes)
• Ends with — Blocks any number ending with these digits

The "starts with" option is particularly useful if you are receiving spam from a specific region or using a particular prefix pattern.

Step 4: Save and verify

Click "Save" and confirm the number appears in your blocked list. Blocked callers will hear a message indicating the number is not in service, and the call won't reach your agents.

One helpful feature: if an agent tries to call a blocked number outbound, they'll see a warning. This prevents accidental contact with numbers you've explicitly chosen to block.

The "unknown caller" problem and workarounds

Here is where Zendesk Talk's blocking hits a wall. The system cannot block calls from "Unknown" or "Anonymous" callers because there is no phone number to evaluate. This is a documented limitation that frustrates many support teams.

If you're dealing with harassment or spam from hidden numbers, you've got a few imperfect workarounds:

Workaround 1: Use omnichannel routing triggers

You can create triggers that route calls with specific characteristics to voicemail or a specialized queue. While you can't block the caller entirely, you can minimize the impact on your main support line.

Workaround 2: Block common anonymous number prefixes

Some carriers use specific prefixes for anonymous calls. You can try blocking these patterns using the "starts with" condition. However, this is hit-or-miss and risks blocking legitimate callers.

Workaround 3: IVR filtering

Set up an Interactive Voice Response (IVR) menu that all callers must navigate before reaching an agent. Legitimate callers will press the appropriate option. Many spam callers, especially automated ones, will not complete the menu and will hang up.

The honest truth is that none of these solutions fully solve the anonymous caller problem. If hidden number harassment is a significant issue for your team, you might need to look beyond Zendesk Talk's native capabilities.

Advanced call filtering options

Beyond basic number blocking, Zendesk Talk offers several tools to filter and manage incoming calls more intelligently.

Using IVR to filter calls

An IVR system acts as a first line of defense. By requiring callers to make selections before connecting to an agent, you naturally filter out many low-quality calls. Zendesk Talk's IVR can:

• Route calls based on menu selections
• Provide self-service options for common requests
• Gather information before an agent takes the call
• Direct suspicious calls to voicemail

Call routing strategies

Smart routing can reduce the impact of unwanted calls even if you can't block them entirely:

• Route unknown callers to a specific queue with longer wait times
• Send after-hours calls directly to voicemail
• Use group routing to distribute suspicious calls across multiple agents

Integration with third-party tools

If Zendesk Talk's native filtering is not sufficient, integrations can extend your capabilities. RingCentral, for example, offers a Zendesk integration with enhanced call filtering features. RingCentral's platform includes AI-powered call handling and more sophisticated blocking options that may address gaps in Zendesk's native toolset.

Best practices for managing unwanted calls

Blocking numbers is just one part of a broader call management strategy. Here are practices that'll help keep your phone support clean and effective.

Document harassment incidents

Keep records of when unwanted calls occur, including timestamps and any identifying information. This documentation is essential if you need to escalate to law enforcement or your telecom provider.

Know when to block versus when to route differently

Not every unwanted call needs blocking. One-time wrong numbers don't require action. Persistent spam or harassment does. Use your judgment based on frequency and severity.

Train agents on handling problematic callers

Even with blocking in place, some unwanted calls'll get through. Make sure your agents know how to:

• End calls professionally but firmly
• Escalate harassment to supervisors
• Document incidents for future blocking

Review your blocked numbers list regularly

Blocked lists can grow stale. Numbers that were problematic six months ago may no longer be an issue. Conversely, new patterns may emerge that require updated blocking rules. A quarterly review keeps your list effective.

Alternative solutions when Zendesk Talk falls short

Zendesk Talk's call blocking is functional but limited. If you need more sophisticated call filtering, several alternatives exist.

eesel AI for intelligent call management

At eesel AI, we approach call filtering differently. Rather than relying solely on number-based blocking, our AI can analyze conversation context, caller history, and intent to make intelligent routing decisions. This means:

• Identifying spam patterns beyond just phone numbers
• Routing calls based on the actual content of the conversation
• Learning from your team's interactions to improve filtering over time

Our AI Agent can handle frontline voice interactions autonomously, filtering out low-value inquiries before they ever reach a human agent. For teams struggling with high call volumes or sophisticated spam operations, this contextual approach often proves more effective than simple number blocking.

Competitor alternatives

Other platforms offer different approaches to call blocking:

Talkdesk provides blocklist management with multiple rejection methods. You can choose whether blocked callers hear a busy signal or a "not in service" message. Talkdesk also allows blocking directly from call logs, which streamlines the process when you identify problematic numbers during review.

The key difference between these platforms often comes down to how they handle edge cases like anonymous callers and how deeply integrated the blocking is with broader call management workflows.

Getting started with smarter call management

Managing unwanted calls in Zendesk Talk starts with understanding what the platform can and cannot do. You've got solid tools for blocking specific numbers and patterns, but you'll need workarounds for anonymous callers and potentially third-party integrations for more sophisticated filtering.

The bottom line? For basic spam and known problematic numbers, Zendesk Talk's native blocking is sufficient. For teams facing persistent harassment from hidden numbers or sophisticated spam operations, you might need to supplement with additional tools or consider platforms with more advanced AI-powered filtering.

If your team's struggling with call volume management beyond what blocking can solve, we'd be happy to show you how eesel AI's approach to intelligent call routing works. You can see eesel in action or try it free to see if it fits your needs.