IVR (Interactive Voice Response):
Auto-Attendant Setup

The terms are often used interchangeably, but technically they describe systems of different sophistication:

• Auto-Attendant: A simpler system that answers calls, plays a greeting, and routes the caller to a predetermined destination based on a single digit press. It follows a fixed script with no dynamic data integration. Most SMBs use an auto-attendant and call it their "IVR."
• Full IVR (Interactive Voice Response): A more sophisticated system that can accept variable-length digit input (phone numbers, account numbers, postal codes), query databases in real time, play personalised responses based on caller data, collect form submissions via keypad, and make intelligent routing decisions based on multiple inputs. Used in banking, utilities, large call centres.

For most businesses, a well-configured auto-attendant in FreePBX delivers everything needed. The terms are used interchangeably in this guide because the practical setup is the same — the distinction matters more at the enterprise level where full IVR integration with CRM and billing systems is required.

Setting up an IVR in FreePBX requires the following steps in order:

• Step 1: Record or upload your greeting audio files via Admin → System Recordings
• Step 2: Create the destinations your IVR will route to (Ring Groups, Queues, Extensions) via the Applications menu
• Step 3: Build the IVR itself via Applications → IVR → Add IVR. Select your greeting, configure timeout settings, and add digit options pointing to your destinations
• Step 4: Create a Time Condition (Applications → Time Conditions) to route business hours calls to the IVR and after-hours calls to an after-hours IVR or voicemail
• Step 5: Set your inbound route (Connectivity → Inbound Routes → your DID) destination to the Time Condition
• Step 6: Click Submit → Apply Config, then test by calling your DID from an external phone

The complete step-by-step configuration is covered in Section 7 of this guide above.

IVR not responding to digit presses is almost always a DTMF (Dual Tone Multi-Frequency) configuration problem. DTMF is the technology that transmits the keypad tones from a caller's phone to your PBX. There are several DTMF transport methods, and a mismatch between your SIP trunk, your PBX, and your phones causes the tones to not be received:

• Most common fix: Ensure both your SIP trunk and your IVR extensions use RFC 2833 (chan_sip) or RFC 4733 (PJSIP) for DTMF. This sends DTMF as out-of-band data packets separate from the audio stream — far more reliable than in-band DTMF.
• In FreePBX: go to your SIP trunk settings → Advanced Options → DTMF Mode → set to rfc2833
• In pjsip.conf endpoint: set dtmf_mode=rfc4733
• Secondary cause: If using G.729 audio codec, in-band DTMF is compressed out of existence. G.729 requires RFC 2833 out-of-band DTMF — in-band will never work.
• Third cause: SIP trunk carrier stripping DTMF. If RFC 2833 is correctly set but digits still not received, capture a SIP trace (sngrep) and verify a=rtpmap:101 telephone-event/8000 appears in the SDP offer.

The research on IVR usability consistently points to the same answer: 4 to 5 options per menu level is the sweet spot. Here is why:

• Fewer than 3 options suggests you could probably handle it more simply without a menu
• 4–5 options gives clear routing for the main departments without overwhelming callers
• 6+ options becomes cognitively difficult to track — callers have to keep all options in memory while listening
• Always include 0 for operator — this is standard and expected, so it does not "waste" a slot conceptually

If you genuinely need more than 5 routing options, consider a two-level menu: Level 1 routes to a category ("Press 1 for commercial services, Press 2 for residential services"), then Level 2 routes to a specific department within that category. This is preferable to offering 8+ options on a single menu.

The ultimate test: time your IVR recording. If reciting all your options takes more than 12 seconds, you have too many. Callers become impatient after 15 seconds in a menu. Keep it tight, keep it fast.

Yes — this is one of the most important and commonly used FreePBX features for businesses. Time-based IVR greetings are implemented using the Time Conditions module combined with separate IVR configurations for each time period. Here is how it works:

• Create multiple IVR configurations: Build a "Business Hours IVR" with your active greeting and department routing, and a separate "After Hours IVR" with your closed message and voicemail option
• Create a Time Condition: Applications → Time Conditions → define your business hours (e.g., Mon–Fri, 9:00–18:00)
• Set Match/No Match: Time Condition Match → Business Hours IVR; No Match → After Hours IVR
• Connect to inbound route: Your DID's inbound route destination points to the Time Condition, which then routes to the appropriate IVR based on when the call arrives
• Add holiday exceptions: Create Time Groups for specific holiday dates (Admin → Time Groups) and add them to your Time Condition — holidays automatically play the holiday greeting regardless of day-of-week settings

You can also use a manual override feature in FreePBX where dialling a specific extension toggles the time condition — useful for unexpected early closures where staff can quickly switch to after-hours mode without changing any configuration. For routing redundancy that protects your IVR deliverability, read: Geo-Redundant Routing Guide.