However, if you have an old installation CD and need to find or use your existing license, here is the most useful content put together for your specific search term.
QuickBooks Pro 2013 requires phone or internet activation through Intuit’s servers. Intuit has likely turned off those specific activation endpoints. When you call the automated line, the system hears “2013” and hangs up. Without activation, the software enters a 30-day countdown, then locks you out of your own financial data. quickbooks pro 2013 license and product number
If you've lost the software or are moving to a new computer, you can still retrieve your info through Intuit's online portals. However, if you have an old installation CD