You could format the cell to show 11 digits:

Format|Cells|Number tab|custom category
00000000000

Or you could precede your entry with an apostrophe:
'12341234123

Or you could format the cell as Text, then do the data entry.

Martin, ©¿©¬, @nohere.net wrote:

Hi
I have a cell with a moblle phone number
0xxxxxxxxxx (11 numbers) & the 0 doesn't show?
Why is that & how do I fix please?
--
Martin
©¿©¬

--

Dave Peterson