Suppose you frequently call services with automated phone menus (phone trees or Interactive Voice Response, IVR) and would like to skip these prompts to reach your desired service or person more quickly. In that case, you may add a certain pause or wait for characters in the phone number stored on your device. This will allow your phone to automatically dial extensions or menu options after connecting to the main number. 

Here's how you can do it on both Android and iOS:

**For Android:**

1. Open the Phone app and go to the Contacts tab.

2. Tap on the + button to add a new contact.

3. Type the main number in the phone number field.

4. Tap on the menu button (three vertical dots) at the top-right corner.

5. Select "Add pause" or "Add wait" from the menu that appears.

   - A "Pause" inserts a 2-second delay before dialing the next digits. A comma usually represents this (,).

   - A "Wait" inserts a delay until you press a key to proceed. A semicolon usually represents this (;).

6. Type the extension or menu numbers you want to be dialed automatically.

7. Finish adding the contact information and save the new contact.


**For iOS:**

1. Open the Phone app and tap Contacts.

2. Tap + to create a new contact.

3. In the phone number field, input the main number.

4. On the bottom-left of the keyboard, tap "+*#”.

5. Here, you can add a "Pause" or “Wait”.

   - A "Pause" will add a comma (,) which is roughly a 2-second delay.

   - A "Wait" will add a semicolon (;) which will pause dialing until you tap Dial.

6. After the pause or wait character, Input the extension or menu numbers.

7. Fill in the rest of the contact's details and tap Done.


**Example:** If you often call a customer service line at 123-456-7890 and need to press 2 for English and then 5 for customer service, you would save the number as follows:

- On Android with pauses: 1234567890,,2,,5

- On iOS with pauses: 1234567890,2,5

The number of commas or pauses can be adjusted based on the phone tree's timing. Some systems might require longer pauses.

Please note that effectiveness can vary depending on the specific phone system you are calling. Some systems may not respond correctly to quickly dialed numbers or might have random lengths of introductory messages.