The number of voicemails you can store before your iPhone voicemail box is full depends primarily on your mobile carrier and voicemail plan, not directly on the iPhone itself. iOS does not impose a specific voicemail storage limit; instead, the limit is set by your carrier's voicemail system

. Here are some typical voicemail capacity limits by major carriers:

• Verizon : Basic voicemail allows storing up to 20 messages with a maximum length of 3 minutes each. Premium Visual Voicemail increases capacity to 40 messages, also typically 3 to 5 minutes each

• AT &T: Basic voicemail supports about 20 messages of 2 minutes each. Visual Voicemail downloads messages to your phone, allowing you to keep them until you delete them, but the carrier box still has limits

• General default : Many voicemail systems have a default maximum capacity of around 100 messages, with a max duration of about 10 minutes per message, but this varies by provider

When your voicemail box is full, callers will hear a "mailbox is full" message and cannot leave new voicemails until you delete some old ones. Visual Voicemail on iPhone downloads messages locally, but the carrier’s voicemail box is the actual limit. Deleting messages frees space on the carrier’s server and allows new messages

. To avoid a full voicemail box on iPhone:

• Regularly check and delete unwanted voicemails.
• Use the "Clear All" feature to quickly free space.
• Save important voicemails elsewhere (e.g., Voice Memos app or cloud backup).
• Adjust voicemail settings if your carrier allows longer storage or automatic deletion

In summary, the voicemail capacity before your iPhone voicemail is full depends on your carrier’s voicemail box limits, commonly around 20 to 40 messages for major carriers like Verizon and AT&T, with message length restrictions also applying. The iPhone itself does not impose a fixed voicemail count limit