For a single withdrawal to close either an employer-sponsored or self-employed Fidelity 401(k), you’ll need to make the request via the Fidelity NetBenefits website. If you don't have an account, create a user name and a six- to 12-digit or character password. After logging in, select your 401(k) account from the home page, click on loans and then on rollovers and withdrawals. Check the withdrawal box and enter 100 percent. Read the tax implication warning and place a check mark in the box at the bottom of the warning message box. Verify your mailing address before clicking the save button to process the cancellation request. An account cancellation doesn't have a direct deposit option; according to Fidelity, it typically takes three to five business days to receive your check.