How Do You Forward Calls to an Answering Service? Turn On Conditional Forwarding
By Sharrk Team · October 23, 2026
To forward calls to an answering service, turn on conditional call forwarding (no answer, busy and unreachable) with your carrier's star codes or phone settings, and point it at the service's number. With Sharrk, that number is your Sharrk number: you keep your existing business line, and Sharrk's AI voice agent answers every call 24/7 or only the calls you miss.
The codes below come from each carrier's own support pages, checked October 23, 2026. Carriers change codes and plans, so confirm on your account before you rely on them.
What is the difference between unconditional and conditional forwarding?
Unconditional (also called "all calls" or "always forward") sends every call straight to the new number. Your phone never rings. Use it when you want the answering service to take every call, such as nights or weekends.
Conditional forwarding sends a call only when something specific happens:
- No answer: you didn't pick up after a few rings.
- Busy: you're already on another call.
- Unreachable: your phone is off, in airplane mode or has no signal.
For most owners who still want to answer their own phone during the day, conditional forwarding is the right setting. You get the first chance at every call, and the service catches the rest.
What are the call forwarding codes for Verizon, AT&T and T-Mobile?
Dial these from the phone whose calls you want to forward, then press Call. Replace "number" with your answering service's 10-digit number.
| Carrier (line type) | All calls | No answer / busy | Unreachable | Turn off |
|---|---|---|---|---|
| Verizon (wireless) | \*72 + number | \*71 + number (covers busy and no answer together) | Not listed separately | \*73 |
| T-Mobile (wireless) | \*\*21\*1 + number # | No answer: \*\*61\*1 + number #; Busy: \*\*67\*1 + number # | \*\*62\*1 + number # | ##004# (all), or ##21#, ##61#, ##67#, ##62# one at a time |
| AT&T (wireless) | Phone settings: Call forwarding > Always forward | Phone settings: When busy / When unanswered | Phone settings: When unreachable | #21# (per AT&T troubleshooting) |
| AT&T Phone for Business (landline) | \*72 + number # | No answer: \*92 + number #; Busy: \*90 + number # | Not listed | \*73# / \*93# / \*91# |
A few notes from the carriers themselves:
- Verizon says that with \*71 your phone rings several times before the call forwards, and you can still make outgoing calls. It also warns that an extra button press during setup can stop the number from being recognized, leaving callers with a busy signal.
- T-Mobile lists the codes on its self-service short codes page, and says calls can only be forwarded to 10- or 11-digit numbers, not international ones.
- AT&T wireless help walks through forwarding from the phone's settings menu (Always forward, When busy, When unanswered, When unreachable) rather than listing star codes, and says forwarding settings can only be changed from the wireless phone itself. Google's Voice help center lists \*61, \*62 and \*67 (each followed by the number and #) for AT&T no-answer, unreachable and busy forwarding, with ##61#, ##62# and ##67# to turn them off.
If you use a reseller or prepaid brand, check with them. Google's help page notes that some resellers and subsidiary providers may not support conditional forwarding.
How do you forward calls on a VoIP or business phone system?
Cloud phone systems usually handle this in an admin portal instead of star codes.
- RingCentral: in the RingCentral app, go to Settings > Phone > Call handling, click Edit, and under Missed calls choose Forward to external number, then enter the answering service's number and Save. RingCentral's developer guide says ring duration is set in seconds and each ring lasts about 5 seconds; when the ringing ends unanswered, the call goes to the no-answer destination.
- AT&T Phone for Business: use the \*72, \*92 and \*90 codes in the table above.
- Other systems: look for "call handling", "missed calls", "no answer" or "find me / follow me" in your admin settings, and set the external number there.
How do you set how many rings before calls forward?
On T-Mobile, you can set the delay when you turn on no-answer forwarding by adding two asterisks and the number of seconds before the final #: \*\*61\*1 + number \*\*seconds#. T-Mobile lists 5, 10, 15, up to 30 seconds. On Verizon, \*71 forwards after "several" rings and the support page doesn't list a way to change that. On RingCentral, set the ring duration in your call handling rules.
How long to let it ring is a business decision. We cover that trade-off in how many rings before answering a business phone, so we won't repeat it here. The short version: set it long enough that you can grab the call if you're free, and short enough that the caller doesn't hang up.
How do you test call forwarding?
- Turn on the forwarding you want (for example, no answer).
- From a different phone, call your business number.
- Let it ring without answering. The answering service should pick up.
- Repeat for busy (call yourself while you're on another call) and unreachable (put your phone in airplane mode and call again).
- Check that the service recorded the caller's details and that you got the message or booking.
If callers hear a busy signal or an error, re-enter the code and check the number, which is Verizon's first troubleshooting step. AT&T notes that if the number you forward to is busy, callers get a busy signal, so make sure the destination can take more than one call at a time. AT&T also notes that call forwarding overrides your wireless voicemail.
How do you turn call forwarding off?
Use the "turn off" code from the table: \*73 on Verizon, ##004# to clear all forwarding on T-Mobile, #21# on AT&T wireless (or turn it off in the phone's settings), and \*73#, \*93# or \*91# on AT&T Phone for Business. Make a test call afterward to confirm your phone rings again.
Do forwarded calls cost extra?
Sometimes. Here is what each carrier says on its own pages:
| Carrier | What its support page says |
|---|---|
| Verizon | No monthly fee for call forwarding on current plans (some retired plans may charge). Airtime charges still apply to forwarded calls, and additional per-minute charges may apply. |
| AT&T wireless | Forwarded calls are billed for the length of the call and may incur long-distance or roaming charges. With some plans, forwarding minutes aren't counted against plan minutes. |
| T-Mobile | Its short codes page doesn't list a charge for forwarding. |
On an unlimited-minutes plan, this usually doesn't show up as a separate charge, but check your own plan. None of these carriers forward to international numbers.
How do you forward your business number to Sharrk?
You don't port your number or change what's on your trucks and website. Sharrk gives you a phone number, and you use ordinary carrier forwarding to send calls to it:
- Only the calls you miss: set conditional forwarding (no answer, busy, unreachable) to your Sharrk number. You answer when you can, and Sharrk's AI voice agent answers the rest.
- Every call, 24/7: set unconditional forwarding to your Sharrk number. Sharrk answers every call and can live-transfer to a person when a caller needs one.
The agent answers, collects the job details, and books the appointment onto Sharrk's calendar, Calendly or Cal.com, or into ServiceTitan. Callers land in Sharrk's built-in CRM, and Strikes (automated follow-up sequences of calls, texts and emails) can pick up from there. For the bigger picture on covering calls without front-desk staff, see how to answer every call without a receptionist.
You don't need to configure any of this by hand. Mako, the AI assistant inside Sharrk, builds your voice agent from a plain-English description of your business, such as your services, hours, service area and how you book jobs, and you can test it before any real calls reach it.
How Sharrk handles forwarded calls
Sharrk Free costs $0, includes 2,500 one-time credits, and lets you build and test unlimited agents with Mako, no card needed. Sharrk Core is $99 a month (or $990 a year) with 47,500 credits a month, one phone number and every feature. There are no contracts or setup fees, and the first payment has a 30-day money-back guarantee, minus usage. See how the AI answering service works, then start free and forward your number, or book a demo and we'll walk you through it.
Related on Sharrk: AI answering service · AI receptionist · How many rings before answering
Sources
- Call forwarding: everything you need to know (Verizon) (checked October 23, 2026)
- Self-service & short codes (T-Mobile) (checked October 23, 2026)
- Calling services (T-Mobile) (checked October 23, 2026)
- Setting up call forwarding (AT&T device support) (checked October 23, 2026)
- Call Forwarding for Wireless (AT&T) (checked October 23, 2026)
- Troubleshoot AT&T Wireless Call Issues (AT&T) (checked October 23, 2026)
- Manage Call Forwarding, AT&T Phone for Business (AT&T) (checked October 23, 2026)
- Send calls to Google Voice voicemail with conditional call forwarding (Google Voice Help) (checked October 23, 2026)
- Setting up user call forwarding in the RingCentral app (RingCentral) (checked October 23, 2026)
- Call Handling Configurations (RingCentral Developers) (checked October 23, 2026)
Frequently asked questions
How do you forward calls to an answering service?
Turn on conditional call forwarding (no answer, busy and unreachable) with your carrier's star codes or phone settings, using the answering service's number as the destination. With Sharrk, you forward to your Sharrk number and keep your existing business number.
What is the Verizon code for conditional call forwarding?
Dial *71 followed by the forwarding number to forward calls when you're busy or don't answer, according to Verizon. Dial *72 plus the number to forward all calls, and *73 to turn forwarding off.
What are the T-Mobile call forwarding codes?
T-Mobile lists **61*1+number# for no answer, **67*1+number# for busy, **62*1+number# for unreachable and **21*1+number# for all calls. ##004# cancels all forwarding.
Can I keep my business number if I use an answering service?
Yes. Call forwarding keeps your number in place and only sends calls to the service's number, so you don't need to port it or change your listings.
Do forwarded calls cost extra?
They can, depending on your plan. Verizon says airtime applies to forwarded calls and additional per-minute charges may apply, and AT&T says forwarded calls are billed for the length of the call, though some AT&T plans don't count those minutes.
How do I turn off call forwarding?
Dial your carrier's off code: *73 on Verizon, ##004# on T-Mobile, or #21# on AT&T wireless. Then call your number from another phone to confirm it rings again.