 <p>Well, the other answer is probably better, but I wrote this anyway, so I'm posting it:</p> <p>Needs:</p> <pre><code>using System.Text.RegularExpressions; </code></pre> <p>Code: </p> <pre><code>string str = "B82V16814133260"; string[] match = Regex.match(str, @"^([\d\w]+?\w)(\d+)$").Groups; string left = match[1]; string right = match[2]; </code></pre>