Excel's precision for numerical entries is 15 decimal digits.
You can either format the cell as Text before entering the number (including
the dashes) or precede the entry with an apostrophe (which will not show in
the cell)
In both cases, it is not a number for Excel anymore, it is text. Probably,
that is what you require as well

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Kind regards,

Niek Otten
Microsoft MVP - Excel

"Neil" wrote in message
...
When I try to format a 16 digit number into 1111-2222-3333-4444 the last
number is displayed as a "0". How do I get the last number to display
correctly?
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Neil