tel:// scheme automatically formats the phone number

Question

I trying to make a phone call with this sample number 639450200901 but it seems iOS sdk automatically formats the phone number. Displaying like this one "+63 945 020 0901" on the alert. Any suggestions for this not to be automatically formatted, i wanted to proceed with the call without this + sign? Here is my sample code:

if let phoneNum = _params["recipient"] as? String,
           let percentEncodedString = phoneNum.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed),
           let url = URL(string: "tel:\(percentEncodedString)") {
        
            if (UIApplication.shared.canOpenURL(url)) {
                   UIApplication.shared.open(phoneNumUrl, options: [:], completionHandler: { ( completed ) in
                      print("Call completed")
            }
    }

Answer 1

As stated in the 10.3 release notes.

https://developer.apple.com/library/content/releasenotes/General/RN-iOSSDK-10.3/

openURL

When a third party application invokes openURL: on a tel://, facetime://, or facetime-audio:// URL, iOS displays a prompt and requires user confirmation before dialing.

So, when you invoke a URL with scheme tel://, phoneNumber will be formatted by the OS, and shown in the prompt. It's a system prompt and we can't do anything about it.

You may however create a custom alert and show phoneNumber in your desired format before the system prompt is shown:

if let phoneNumber = phoneNumber, let phoneURL = NSURL(string: ("tel://" + phoneNumber)) {

    let alert = UIAlertController(title: ("Call " + phoneNumber + "?"), message: nil, preferredStyle: .alert)
    alert.addAction(UIAlertAction(title: "Call", style: .default, handler: { (action) in
        UIApplication.shared.open(phoneURL as URL, options: [:], completionHandler: nil)
    }))

    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
    self.present(alert, animated: true, completion: nil)
}

For more info on phone links, please check: Apple URL Scheme Reference

You may find more details on URLs for Telephone Calls, how phone numbers are formatted when a telephone URL is being parsed by the mobile OS here RFC 2806 .