How do you forward calls only when you don't answer?

Ordinary forwarding sends every call somewhere else. Conditional forwarding sends a call on only in certain cases, so you still get the ones you pick up. AT&T's phone settings name three cases⁴: when busy, meaning you are already on another call; when unanswered, meaning you don't pick up after a few rings; and when unreachable, meaning your phone is off, in airplane mode or out of signal.

Forwarding takes the place of your voicemail. AT&T says so plainly: call forwarding overrides your wireless voicemail³. If you forward unanswered calls to an answering service or AI receptionist, those callers reach it instead of your voicemail box. If the number you forward to is busy, AT&T says your callers hear a busy signal³, so forward to a line that can take more than one call at a time.

On Verizon wireless, dial *71 and the 10-digit number you want calls sent to. Verizon calls this No Answer/Busy Transfer: calls forward when your phone is busy or not answered¹. Listen for the beeps and let the call end on its own. *72 forwards every call instead, and *73 turns call forwarding off². Verizon notes that star codes may not work when you are outside its coverage area¹.

Phones on GSM networks follow a shared international standard, 3GPP TS 22.030, and AT&T and T-Mobile run GSM-family networks. The standard gives each condition a number: 61 for no reply, 67 for busy, 62 for not reachable and 004 for all three at once⁵. To set one, dial two stars, the code, a star, the number and a pound sign, such as **61*5551234567#. To clear it, dial ##61#⁵. Not every carrier supports every code, so check the result in your phone's settings afterwards. On an AT&T phone you can also skip the codes and set each condition under Settings, Calling accounts, Call forwarding⁴.

T-Mobile publishes its own code list, but its support site refused our requests on 4 November 2026, so we have not copied it here. Use the standard codes or your phone's settings, and confirm on T-Mobile's own page or with T-Mobile.

A landline or business phone works differently. AT&T Phone, AT&T's home and small-business line, uses *92 for no-answer forwarding and *90 for busy forwarding, each followed by the number and #. *93# and *91# turn them off⁶. Verizon Business Digital Voice uses a web portal instead of codes: open Call Settings, turn on Call Forwarding and choose When busy or When no answer⁷.

It depends on the service. Verizon wireless forwards an unanswered call after three to six rings¹. It does not let you set an exact count with *71.

On GSM-standard phones you can set the delay yourself. The standard's no-reply timer runs from 5 to 30 seconds⁵. Add it to the end of the code: **61*5551234567**15# forwards unanswered calls after 15 seconds. Verizon Business Digital Voice asks how many rings you want when you choose When no answer⁷. AT&T's Phone page gives no ring count for *92⁶.

Pick the shortest delay that still lets you answer the calls you want to take yourself. Every extra ring is time a caller spends waiting before anyone answers.

Forwarded calls usually aren't free. Verizon says that without unlimited minutes, forwarded calls are billed under your plan². AT&T bills them for the length of the call, adds long distance or roaming charges where they apply, and notes that on some plans forwarded minutes don't count against your included minutes³. If the call goes to an answering service, that service usually counts its own minutes too, so one forwarded call can show up on two bills. Check both before you forward every call.

Test it the way a customer would. From a second phone, call your number and let it ring without answering. Then call again while you are on another call. Then switch your phone to airplane mode and call once more. Each call should reach the number you chose. If any of them lands in your old voicemail, that condition isn't set.

Carriers change these codes and settings from time to time. This page reflects their own support pages and the 3GPP standard as of 4 November 2026.