Description: A phone number format in calc would keep the leading zero and have a user specified alignment. Actual Results: leading zero removed Expected Results: not removed Reproducible: Always User Profile Reset: No Additional Info: none
Phone "numbers" are not numbers (amounts used to calculate). Thus, the cells where phone numbers (and other identifiers, possibly resembling numbers) are stored, must be pre-formatted as text; or the identifiers must be entered with leading apostrophe ('). Importing from CSV must also set the data type for the columns with such identifiers as text. To emphasize the importance, and show that it is not just a cosmetic issue or a nitpicking: for identifiers longer than 15 digits, it is simply impossible to store all the digits in a numeric data; so unless one properly imports/enters these digits as text, an identifier like 1234567890123456789 will be rounded to 1234567890123460000, loosing the last digits irreversibly.
Numeric values _never_ preserve a leading zero and the maximum representable integer value is 9007199254740991 (2^53-1). As Mike said, either pre-format the cell with the Text format before entering the value, or in a General formatted cell enter the phone number as text string by prepending a leading ' apostrophe, like '012-345-678901 However, to display a numeric value such, you could use a format code like [<=9999999]###-####;[<=999999999]"0"##-###-####;"0"##-###-###-#### See also https://help.libreoffice.org/7.6/en-GB/text/shared/01/05020301.html?&DbPAR=CALC That would display 4567890 => 456-7890 34567890 => 03-456-7890 234567890 => 023-456-7890 1234567890 => 0-123-456-7890 91234567890 => 09-123-456-7890 891234567890 => 089-123-456-7890 Note that phone number formats differ between locales, so adjust the format code to your needs. Also, it is not possible to display the same number different depending on the net provider or area code, so differentiating between 012-3456789 and 0123-456789 is not possible. The only way to do it properly is using text instead of numeric.