Put an upper limit on that match, say you want between 5 and 7 digits: 
my $ID = 0123456;
if ($ID =~ /\d{5,7}/ {
    do this...
}

[download]
So for your case, perhaps /\d{5,5}/

In reply to Re: specific numbers of digits by lacertus
in thread specific numbers of digits by emichswimr

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