After you file


@Tech8789 wrote:

What happens if I forgot to put the income into the return? Should I let them just figure out the issue and they’ll mail me? Or its worse case scenario? 


Income taxes are partly on the honor system.  If you have income that is not reported to the IRS by the payer, you are still required to report that income and pay taxes on it, using your own accurate personal or business records.  

 

When a 1099 is issued, the IRS computers will look for matching income on your return, and if they don't find it, they will send you a letter and sometimes a tax bill.  If the income is not reported by the payer, the IRS computer does not have a specific way to identify you as a tax cheat, but they can and do perform both random and targeted audits.  If you are found to have intentionally under-reported your income, you can pay a large fine.