The number of rings before an iPhone goes to voicemail is not controlled by the iPhone itself but by your mobile carrier. Typically, the default ring time is about 20 seconds, which translates to roughly 3 to 6 rings depending on the carrier. Some carriers allow you to customize this ring time, usually between 15 and 30 seconds, or equivalently from 1 up to 6 rings

. To change the number of rings before voicemail, you generally need to contact your carrier or use specific dial codes provided by them. For example:

• T-Mobile: You can set the ring time by dialing a code like *61*<voicemail number>**<seconds># on your iPhone, where <seconds> can be up to 30 seconds (about 12 rings). After dialing, press call to activate the new ring time

• AT &T: You can change the number of rings (from 1 to 6) by logging into your AT&T account online under voicemail settings or by calling customer service

• Other carriers (like giffgaff): You can extend ring time by dialing codes such as **61*443*10*<seconds># where <seconds> can be 5, 10, 15, 20, 25, or 30 seconds, then pressing call

In summary, the iPhone typically rings between 3 to 6 times (about 20 to 30 seconds) before diverting to voicemail, but this can be adjusted by carrier settings or dial codes specific to your provider

. Check with your carrier or their online account management tools to customize this setting.