Buy and sell domain names. If you’re good at finding popular yet undiscovered domain names, you can make some cash on the side by buying and reselling websites. Think of it as digital real estate speculation. Domains are available on GoDaddy.com for as little as $2.99 per year, but are sometimes resold at far higher prices: According to Business Insider, the site MM.com sold for $1.2 million dollars in 2014. Once you find the perfect domain name to resell, you can market it on Flippa.com for a flat fee.
I think what you’re asking is how you can make extra money to pay your real estate taxes. If that’s the case, it depends on your current financial situation, the amount of your estate taxes, your skills, and more. If you visit the “Make Money” section of our website, we have a few articles with different ideas that may be helpful for your situation: https://www.dollarsprout.com/category/make-money/
Double check yourself, before you double wreck yourself. Make sure everything you send to a company, whether a résumé, an email or a portfolio, is good to go. Double check your grammar and wording, and for God’s sake use spell check! This is especially important when it comes to the company’s name. Don’t spell their name wrong and be sure to type it how they type it (e.g. Problogger, not Pro Blogger).
This is an example of passive income that isn't quite as passive as it may seem. Yes, if you own one or more homes or apartments you can collect regular rent checks from your tenants. But in exchange for that, you need to keep the properties in good working order, along with insuring and paying taxes on them. You may need to chase down rent checks from some tenants, too, and you may have several months without rent checks when you're between tenants.