National Instruments offers a fully functional 30-day trial of the latest Circuit Design Suite (currently version 14.4 or higher). While not exactly 14.3, the interface and features are nearly identical. No credit card required — just an email address.
Be wary of:
The second option is illegal and dangerous. Here’s why: Ni Multisim 14.3 Serial Number
If you have already purchased the software or have access through a university, you can usually find your serial number in the following places: Included in your software kit. Confirmation Email: Sent by NI after an online purchase. National Instruments offers a fully functional 30-day trial
Instead of hunting for a cracked serial number, follow this ethical, safe path: Be wary of: The second option is illegal and dangerous
If you can’t afford Multisim, the open-source alternatives above are free and increasingly capable. For advanced features, the NI trial gives you 30 days to complete projects.