I only need to fax documents once in a while, so I don’t want to commit to a monthly subscription. Is there a way to fax online for free or with a pay-per-use model?

Yes, that was exactly my situation! I was only faxing stuff occasionally and didn’t want a pricey plan. What really helped was guide on fax online. It goes through several services and clearly points out which ones offer free plans or let you pay per fax. I tried one of the recommended ones, and the process was super simple — just upload the file, enter the number, and hit send. No need for a machine or long registration. That article saved me from wasting time testing shady websites. If you're faxing rarely, it's the perfect place to start.