What is call forwarding?

Forwarding lives at the carrier, not on your handset and not in any app. That is why switching it on takes minutes, and why it works the same from a mobile, a landline or a VoIP line.

There are three modes worth knowing. Unconditional sends everything. Busy-or-no-answer sends only what you miss. Time-based switches at set hours if your provider supports a schedule.

On most mobile carriers you set it with a star code and cancel it with a hash code. Business and VoIP lines use a dashboard instead, which usually gives you more control.

Say you run a two-person landscaping crew and your business line is your own cell. You want calls you can't answer to go to 555-0142 (a placeholder) after about 20 seconds. On carriers that use the standard GSM codes, which include AT&T and T-Mobile, you'd dial **61*5550142**20# and press call. That last 20 is the delay in seconds, and it accepts 5 to 30 in steps of five.

Verizon and many landlines use a different family: *71 plus the number for no-answer forwarding, *72 for everything, and *73 to cancel. Codes change, so confirm on your carrier's support page before trusting a forum post or this paragraph.

Why 20 seconds? A US ring cycle lasts six seconds, two of ringing and four of silence, so 20 seconds is a little over three rings. You get a fair chance to grab the phone yourself, and the caller doesn't sit through six.

Forwarding fails silently. Your phone won't warn you that a carrier update reset the setting or that a new SIM wiped it, and callers simply land in your old voicemail again. You find out two weeks later when a customer mentions the message they left.

Build a small habit around it. On the first Monday of each month, call your business number from a different phone, let it ring out, and see where it lands. Do the same after any phone upgrade, SIM swap, plan change or carrier switch. If your carrier offers a status code, use it (on GSM carriers, *#61# shows the no-answer forward), but trust the test call more. It takes thirty seconds and checks the whole chain, from the carrier setting to wherever your calls are supposed to end up.

GreetKeeper gives you a destination number and the exact code or dashboard path for your carrier, so you are not guessing at star codes from a forum thread.

Your first test call shows up as a transcript within a minute, which is a more reliable confirmation than the carrier's beep.

Stopping is the same setting in reverse. Cancel the forward and your line does exactly what it did before, with nothing ported and nothing to reprint.