Here are some of the main rules: ​

1. No Doing Business with Family: You can’t use your SDIRA to do business with certain family members like your parents, kids, or spouse. ​ You might have to pay a big fine if you break this rule. ​
2. No Buying Certain Things: You can’t use your SDIRA to buy life insurance or most collectible items, like art, stamps, or fancy coins. ​
3. Paying Taxes on Some Income: If your SDIRA earns money from a business that is not related to your investment, you might have to pay taxes on that money. ​
4. Must have a Helper: You need a custodian, to take care of your SDIRA. ​ They make sure you follow the rules and keep records for the IRS. ​
5. Taking Money Out at the Right Time: When you get older (72 years old), you have to start taking some money out of your SDIRA. ​ If you don’t, you might have to pay a big fine. ​
6. Limit on How Much You Can Add: You can only add a certain amount of money to your SDIRA each year. ​ In 2021, the limit is $6,000 or $7,000 if you are 50 years old or older. ​
7. No Borrowing Money: You can’t borrow money from your SDIRA or use it to help you get a loan. ​
8. Know How Much Your Investments Are Worth: You have to find out how much your SDIRA investments are worth each year. ​ This can be hard for some things, like real estate or private businesses, and you might need help from an expert. ​

Many other rules exist beyond this one, which makes it very difficult to use an SDIRA without getting into trouble.