Here’s how you can easily find your system serial number in CheckMark Software, whether you’re using Windows or macOS.

How to Find Your System Serial Number on Windows Versions

1. Open CheckMark Software.
2. Click Help in the upper menu.
3. Select the corresponding About option for the CheckMark Software you are using:
   • CheckMark Payroll: About CheckMark Payroll
   • CheckMark MultiLedger: About MultiLedger
   • CheckMark 1099: About CheckMark 1099
   • CheckMark 1095: About CheckMark 1095
4. A pop-up window will appear displaying your system serial numbers — Baseboard, BIOS, or UUID.

---

How to Find Your System Serial Number on macOS Versions

Every Mac computer has a unique system serial number. You can find your serial number in CheckMark applications in a few simple steps:

1. Open CheckMark Applications.
2. Click the application name in the top-left corner.
   • CheckMark Payroll: CheckMark Payroll_64 (or) CheckMark Payroll_32
   • CheckMark MultiLedger: MultiLedger_64 (or) MultiLedger_32
   • CheckMark 1099: CheckMark 1099 Print_64 (or) CheckMark 1099 EFile_64
   • CheckMark 1095: CheckMark 1095 Print_64 (or) CheckMark 1095 EFile_64
3. Select the corresponding About option:
   • CheckMark Payroll: About CheckMark Payroll
   • CheckMark MultiLedger: About MultiLedger
   • CheckMark 1099: About CheckMark 1099
   • CheckMark 1095: About CheckMark 1095
4. A pop-up window will appear displaying your System Serial Number.