It’s easy to start a SEP IRA with Betterment. When opening up a SEP IRA with Betterment, we’ll simply ask you to complete IRS Form 5305 and keep it for your own records. You do not need to mail this form to the IRS or to Betterment. To start a SEP IRA with Betterment: Navigate to Home Click “Add New” on the menu Choose the SEP IRA option (from the “Tax-advantaged Retirement” section) Download and complete IRS Form 5305 and keep it for your records. You do not need to mail this form to the IRS ...