Phone Number Format Change - Bulk Add Country Code and Remove Dashes

Phone Number Format Change - Bulk Add Country Code and Remove Dashes

In the past I would create a new customer in my Zoho Books, and enter their phone number in the format customary for the USA (that's where we are domiciled):
Areacode-Prefix-Number
234-456-6789
This scheme is important as many other software packages understand data formatted like that as a phone number.
+1 country code is hardly ever used in the US (unless you are doing business across the globe).

Some time ago, ZOHO has changed the input format for phone numbers (to address international customers, I guess) to:
+CountrycodeAreacodePrefixNumber
+12344566789

So, for US customers that's rather unusual (as we hardly ever specify "+1" country code, and dashes "-" are customarily added)

So this new scheme comes with some drawbacks.  Below is a screen grab to illustrate.


I have hundreds of contacts that use the old format.  Sending messages to those numbers worked for years.

Do I need to update them all by hand one-by-one?

Couldn't Zoho just write a script and automatically "fix" phone numbers to US-located contacts on the back end?

Is there a write-up on how to automate this process?

Also, I find it hard to believe that your web coders cannot program the client contact form (for US customers) to instantly change the customary syntax of 234-456-6789 to what your database is expecting +12344566789 while the numbers are entered into that field.
That's as basic as it gets and great many sites do that automatically.

So to summarize:
1. Can you code the contact form to convert US customary phone number format to what you want us to enter?
2. Can you provide an automated way of converting old US phone numbers (by adding "+1" and removing "-" dashes)?
3. Can you at least do a write-up how to automate this conversion process?