[Samples Included] AI Apps are Recommended for Changing Voicemail Voices! A Thorough Guide on How to Create Greeting Messages
Jan. 26, 2026

When you make a call, you might hear an answering machine's outgoing message.
You can change the answering machine voice on smartphones and business phones to any content you like.
In fact, by using an AI voice synthesis service, you can easily create outgoing messages for your answering machine.
In this article, we will explain in detail how to change the voice of your answering machine's outgoing message.
In addition to changing the voice on iPhone, we will also introduce answering machine setup methods for each carrier, such as docomo, au, SoftBank, and Rakuten Mobile, along with ready-to-use sample phrases.
If you want to change the voice of your answering machine's outgoing message, why not try setting it up for free by referring to this article?
[Free] Latest AI Voice Synthesis Service Recommended for Changing Answering Machine Voices
If you want to change the voice of your answering machine's outgoing message, Ondoku is recommended!
Ondoku is a free AI service using the latest voice synthesis engine that allows anyone to easily create narration audio.
Since it is a web app used from a browser, it is easy to use without installation.
It can read text in a wide range of voices, including female and male voices (Click here for Japanese voice samples).
Because it can read in an easy-to-hear, clear voice unique to the latest AI, it is perfect for answering machine outgoing messages.
It can be used not only for business phones but also for iPhone's standard answering machine features and outgoing messages for carriers such as docomo, au, SoftBank, and Rakuten Mobile.
Furthermore, Ondoku allows you to create answering machine outgoing messages for free!
When using it for free, please include a message at the end of the audio stating that you are using Ondoku.
A paid plan subscription is required for commercial use (Click here for details on commercial use).
If you want to change the voice of your answering machine's outgoing message, why not try utilizing Ondoku?
[Free] Explaining How to Create Answering Machine Outgoing Messages with the Latest AI

If you want to create an answering machine outgoing message, the AI voice synthesis service Ondoku is recommended.
By using Ondoku, you can have your outgoing message read in a female or male voice and change the voice for free.
Now, let's explain how to create outgoing messages that can be used on iPhone, docomo, SoftBank, and Rakuten Mobile.
1. [With Sample Phrases] Write the Script for the Answering Machine Outgoing Message

First, create the script text for the outgoing message to be read by Ondoku.
The key is to make the content of the outgoing message concise and easy to understand.
Any software or app like Notepad or Word is fine to use.
We will introduce sample phrases for answering machine outgoing messages, so please refer to them to write the outgoing message that is perfect for you.
Sample Outgoing Message for Personal Answering Machine
When changing the outgoing message for a personal smartphone's answering machine, simple content like this sample phrase is recommended.
I am unable to answer the phone right now. Please leave a message after the beep.
Sample Outgoing Message for Outside Business Hours
Answering machine outgoing messages are an important factor in determining the first impression for the caller.
When changing the voice of an outgoing message for an IVR system or business phone at a store or office, polite and easy-to-understand content like this sample phrase is recommended.
Thank you for calling. This is ○○ Co., Ltd. We are currently outside of business hours. Our business hours are from 9:00 AM to 6:00 PM on weekdays. We apologize for the inconvenience, but please call back during our business hours.
Sample Outgoing Message for Regular Holidays
To provide detailed service, it is also recommended to create separate outgoing messages for after-hours and regular holidays.
For example, a sample phrase like this is recommended.
Thank you for calling. This is ○○ Co., Ltd. We are very sorry, but we are closed today for our regular holiday. Our store is closed every Wednesday and the third Thursday of each month. We are open from 10:00 AM to 7:00 PM on business days. We apologize for the trouble, but please contact us again on a business day.
Sample Outgoing Message for Temporary Closures
With an AI voice synthesis app, you can quickly prepare audio even for sudden closures.
Why not try creating audio by referring to this sample phrase?
Thank you for calling. This is ○○ Co., Ltd. We are sorry to inform you that we are temporarily closed today due to unforeseen circumstances. We will resume normal operations from tomorrow, [Month] [Day]. Thank you for your understanding.
Sample Outgoing Message for Year-End and New Year Holidays
Even for year-end and New Year holidays, it is recommended to utilize answering machine outgoing messages like this sample phrase.
Thank you for calling. This is ○○. We would like to inform you about our operations during the year-end and New Year holidays. We will be open until 5:00 PM on December 28th. We will resume business from 10:00 AM on January 5th. New Year's operations will begin on [Month] [Day]. Thank you for your continued support this year. We sincerely wish you a healthy and happy New Year.
Sample Outgoing Message for Obon Holidays
Here is a sample phrase for Obon holiday closures.
Thank you for calling. This is ○○ Co., Ltd. We are sorry to inform you that we will be closed for the summer holidays from August ○ to August ○. We will resume normal operations from August ○. We apologize for any inconvenience and appreciate your understanding.
Sample Outgoing Message for Renovations or Construction
Guidance can also be provided via outgoing messages during renovations or construction.
For example, a sample phrase like this is recommended.
Thank you for calling. This is ○○ Co., Ltd. We are sorry to inform you that we are closed from [Month] [Day] to [Month] [Day] for store renovations. We will resume normal operations on [Month] [Day]. We look forward to seeing you again. We apologize for the inconvenience and appreciate your understanding.
2. [Free] Read the Answering Machine Outgoing Message with "Ondoku"
Once you have written the script for the outgoing message, you can have it read aloud for free using Ondoku.
Using the free AI voice synthesis app Ondoku is very simple.
First, open the Ondoku top page.
Paste the script text into the text box on the top page.

As an example, we will read the personal answering machine outgoing message from the sample phrases.
Since we are reading it for free this time, we have added content at the end of the script text stating that it is being "read by Ondoku."
Choose the language and voice.

For Japanese, you can select from over 16 types of voices, including female and male! (Voice samples here)
This time, we will use "Nanami (Guidance)," which is ideal for answering machine outgoing messages.
Ondoku also allows you to adjust reading speed and pitch, but for the first reading, the default settings are fine.
Now, preparation is complete.

Press "Read" to start the free voice synthesis.
Voice synthesis is completed in just a few seconds with the latest AI.

The screen will switch, and the audio player will be displayed.
By reading this script text, audio like this was generated.
If there are no issues after listening, press the "Download" button to save the MP3 audio file.
*Download in WAV format is also possible from the history page.
Now you have successfully synthesized the audio file for the answering machine outgoing message for free with Ondoku.
3. Change the Voice of the Answering Machine's Outgoing Message

Finally, use the created audio file to change the voice of the answering machine's outgoing message.
How to Change Voice for IVR Systems, Cloud PBX, and Business Phones
For IVR systems, Cloud PBX, and business phones in stores or offices, you can change the outgoing message by directly importing MP3 or WAV files.
Simply open the answering machine settings from the management screen and upload the created MP3 or WAV file.
It is possible to set an outgoing message that matches the company's image, such as a female or male voice.
Since IVR systems, Cloud PBX, and business phones can import audio files as they are, you can easily change the voice using an AI text-to-speech app.
Details about IVR system audio are explained in this article, so please check it out.
How to Change Voice for iPhone, docomo, au, SoftBank, and Rakuten Mobile
For iPhone standard features and answering machine services from carriers like docomo, au, SoftBank, and Rakuten Mobile, you change the outgoing message via the settings screen or telephone guidance.
Even if there is no feature to upload audio files directly, you can change the voice by playing the audio file on a smartphone or computer and recording it using the answering machine's recording function.
*Methods for changing voices on iPhone, docomo, au, SoftBank, and Rakuten Mobile will be introduced later in this article.
In this way, by using the AI voice synthesis service Ondoku, anyone can easily create answering machine outgoing messages for free!
When using it personally, free use is OK if you include "using Ondoku" in the audio!
A paid plan subscription is required for commercial use (Click here for details on commercial use).
Since you can start reading immediately without installation, why not experience Ondoku's AI narration for free?
How to Change the Voice for iPhone Answering Machine Outgoing Messages

From here, we will explain the voice change method for iPhone and carrier answering machine services like docomo, au, SoftBank, and Rakuten Mobile.
First is the method for changing the standard iPhone answering machine voice.
How to Change Voice for iPhone Answering Machine Outgoing Messages
To change the iPhone answering machine outgoing message, first open the Phone app.
The subsequent steps differ depending on whether you have the unified layout or the classic layout.
How to Change Voice if the iPhone Phone App has a Unified Layout
When the iPhone Phone app is in the unified layout, first tap "Calls" and then "Edit" on the screen.
Tap "Edit Answering Machine Outgoing Message" on the Edit screen.
On the screen that opens,
"Custom" → "Record"
Tap this to record the outgoing message.
You can change the outgoing message voice by playing the created audio file on a PC or smartphone and recording it with your iPhone.
How to Change Voice if the iPhone Phone App has a Classic Layout
When the iPhone Phone app is in the classic layout (where the bottom is divided into "History," "Contacts," etc.), first tap "Voicemail".
Tap "Greeting" in the upper right corner of the "Voicemail" screen to open the menu.
In the menu that opens,
"Custom" → "Record"
Tap this to record the outgoing message.
By playing the created audio file on a PC or smartphone and recording on this screen, you can change the voice of the outgoing message.
iPhone Answering Machine Outgoing Messages Can Be Easily Changed in the Phone App
As described, iPhone answering machine outgoing messages can be easily changed within the Phone app.
Because it can be changed more easily than carrier answering machine services like docomo, au, SoftBank, and Rakuten Mobile, it is a recommended feature for iPhone users.
[By Carrier] How to Change Voice for docomo, au, SoftBank, and Rakuten Mobile

Next, we will explain how to change the answering machine's outgoing message voice for each carrier: docomo, au, SoftBank, and Rakuten Mobile.
How to Change docomo Answering Machine Outgoing Message Voice
If you are using a docomo mobile line, you change the answering machine outgoing message by calling docomo's automated response number.
At this time, make sure you can play the created audio file on a computer or another smartphone.
- Open the Phone app and call the docomo voicemail service number "1416".
- The automated response message will play; press "9" (Change service content).
- When the next automated message plays, press "2" (Confirm/Change outgoing message).
- When the following automated message plays, press "2" (Record with your own voice).
- You can then record the outgoing message after the beep.
- Play the audio file on a computer or another smartphone to record the outgoing message.
- When finished recording, press "#" to end recording.
- The recorded content will play; confirm it, and if there are no issues, press "1" (Press "2" to record again).
- The guidance voice will play; press "*", "*", and the "End Call" button to finish.
Through this process, you can change the voice of the outgoing message for the docomo voicemail service.
For docomo, recording up to 3 minutes is possible.
How to Change au Answering Machine Outgoing Message Voice
On au mobile lines, you can change the voice of the outgoing message if you have a contract for "Voicemail Service EX."
Changing the outgoing message for Voicemail Service EX is done by calling au's automated response number from the Phone app.
Ensure beforehand that you can play the created audio file on a computer or another smartphone.
- Call the au voicemail service number "1414" from the Phone app.
- When the automated message plays, press "1".
- Press "1" again at the next automated message.
- Recording will start, so play the audio file on a computer or another smartphone to record the outgoing message.
- When finished recording, press "#" to end recording.
- The automated message will play; press "#".
- Press the "End Call" button to disconnect.
Through this process, you can change the outgoing message voice for au's "Voicemail Service EX."
For au as well, recording up to 3 minutes is possible.
How to Change SoftBank Answering Machine Outgoing Message Voice
When changing the voice of an answering machine outgoing message on a SoftBank mobile line, you also call SoftBank's automated response number from the Phone app.
Ensure beforehand that you can play the created audio file on a computer or another smartphone.
- Call the SoftBank voicemail service number "1416" from the Phone app.
- When the automated message plays, press "2" (Change service settings).
- When the next automated message plays, press "3" (Record, delete, or play original outgoing message).
- Press "3" (Record original outgoing message) at the following automated message.
- Recording starts after the beep, so play the audio file to record the outgoing message.
- When finished recording, press "#".
- The automated message will play; press "9" (Register the recorded message).
- Press "#" to register the recorded audio as the outgoing message.
- When the automated message plays, press "2" (Outgoing message settings).
- When the next automated message plays, press "2" (Set to original outgoing message).
Now you have changed the voice of the SoftBank answering machine's outgoing message.
For SoftBank, recording up to 1 minute is possible.
How to Change Rakuten Mobile Answering Machine Outgoing Message Voice (For Business)
If you are using Rakuten Mobile as an individual, you can only use the standard outgoing messages provided.
If you have a business contract, you can change the voice of the answering machine's outgoing message using the Rakuten Link Office app.
- First, open the Rakuten Link Office app.
- Tap "Settings" from the menu.
- Tap "Calls and Messages" in Settings.
- Tap "Voicemail Settings" in Calls and Messages.
- Tap "Recorded Voice" in Voicemail Settings.
- The recording screen will open.
- Press the microphone button on the recording screen to start recording.
- Play the audio file on a PC or another smartphone to record.
- Tap the microphone button to stop recording.
- Enter a name for the outgoing message and save the recorded audio.
- Tap "Complete Recording."
Now you have changed the voice of the answering machine's outgoing message in Rakuten Mobile's Rakuten Link Office app.
Explaining Recommended Tips for Creating Answering Machine Outgoing Messages

When creating an answering machine's outgoing message, it is recommended to keep a few points in mind.
From here, we explain the tips for creating answering machine outgoing messages.
Points for Selecting a Voice: Features of Female and Male Voices
One important thing when creating an answering machine outgoing message is whether to choose a female or male voice.
Since each has different characteristics, it is recommended to use them according to the application and purpose.
Female Voices Give a Soft and Friendly Impression
A feature of female voices is that they can provide a soft and friendly impression.
Female voices are particularly recommended for answering machines in the customer service and service industries.
By choosing a female voice, you can create a warm outgoing message.
Many types of female voices are available on Ondoku as well.
For example, the female voice "Nanami (Guidance)," which is ideal for guidance, is perfect for changing the voice of an answering machine's outgoing message.
If you are unsure about the type of voice, choosing a female voice is recommended.
Male Voices Feature a Sense of Trust and Stability
A feature of male voices is that they can provide a sense of trust and stability.
For answering machines in highly specialized industries such as law firms or consulting firms, male voices are recommended.
Many types of male voices are also provided on Ondoku, so you can create outgoing messages in a male voice according to your business operations.
Choosing Between Female and Male Voices Based on Corporate Brand Image
It is also recommended to choose between female and male voices according to the corporate brand image.
For a youthful and energetic company, a bright female voice is recommended.
For a company that values tradition and formality, a calm, lower-toned male voice is ideal.
On Ondoku, many female and male voices are available.
Voice samples are introduced in this article, so please check it out.
Outgoing Messages Are Best When Not Too Long
One thing to be careful about with answering machine outgoing messages is making sure they are not too long.
Carriers like docomo, au, and SoftBank allow recording up to 1–3 minutes, but it is actually recommended to make them much shorter.
The optimal length for an answering machine's outgoing message is about 15 to 30 seconds.
The person calling wants to convey their business quickly, so an outgoing message that is too long can cause stress.
When thinking about the content of the outgoing message, conveying the necessary information in a short duration is recommended.
For store or office answering machines,
- Company name
- Current status (outside business hours, temporary closure, etc.)
- Business hours
It is recommended to convey such content.
In the case of a personal answering machine,
- Statement of absence
- Promise to call back
Just conveying these is enough.
With the AI voice synthesis app Ondoku, you can remake outgoing messages as many times as you like, so it is recommended to create various messages and actually listen to them.
Why Not Change the Voice of Your Answering Machine's Outgoing Message with the Latest AI?
In this way, answering machine outgoing messages can be easily created with the AI voice synthesis app Ondoku.
By choosing your favorite voice, such as a female or male voice, you can create easy-to-hear outgoing messages.
On business phones and IVR systems, voice changes can be easily made by importing audio files.
On iPhone, docomo, au, SoftBank, and Rakuten Mobile as well, you can change the outgoing message to any content you like.
To provide detailed service at a store or office, creating outgoing messages with the latest AI is recommended.
Why not try creating your own answering machine outgoing message for free with the AI narration app Ondoku?
■ AI voice synthesis software "Ondoku"
"Ondoku" is an online text-to-speech tool that can be used with no initial costs.
- Supports approximately 50 languages, including Japanese, English, Chinese, Korean, Spanish, French, and German
- Available from both PC and smartphone
- Suitable for business, education, entertainment, etc.
- No installation required, can be used immediately from your browser
- Supports reading from images
To use it, simply enter text or upload a file on the site. A natural-sounding audio file will be generated within seconds. You can use voice synthesis up to 5,000 characters for free, so please give it a try.
Email: ondoku3.com@gmail.com
"Ondoku" is a Text-to-Speech service that anyone can use for free without installation. If you register for free, you can get up to 5000 characters for free each month. Register now for free
