Form FS 2231 at a glance
What it is: FS Form 2231 is a Department of the Treasury, Bureau of the Fiscal Service form you may use to provide instructions for processing your net salary.
Who signs: Sign and date the request form after you have carefully read the instructions and Privacy Act Statement.
The employee must complete items 1, 2, 3 and 5.
What to bring and attach to Form FS 2231
A voided personal check/sharedraft may be attached in lieu of completing Direct Deposit Account Information.
A filled-in Form FS 2231 example: net pay to a checking account

How to fill out Form FS 2231, box by box
Employee Information
Always complete Employee Information: the Employee Payroll Identification Number (SSN), the Employee Name as on payroll records (Last, First, Initials), and the Telephone Number (Work) and (Home).
Type of Account
Put an X in the appropriate space to indicate a checking or savings account and type of payment.
The types of payment are Net Pay, Travel and Other Federal employment related payments.
Direct Deposit Account Information
Enter your financial institution's 9-digit routing transit number, your account number at your financial institution, the depositor's name on the account to which payments are to be directed, and the name of the institution to which payments are to be directed. The Routing Transit Number (RTN) can be obtained from the financial institution or found on the bottom of a check.
If your check or sharedraft includes "payable through" under the bank name, contact the financial institution to help obtain the correct Routing Transit Number for Direct Deposit processing.
Include dashes where the symbol appears on the check or card.
Allotment Information
Complete Allotment Information only if you want to start, cancel or change the amount of a savings or discretionary allotment.
If Savings is checked, the specified allotment is credited to an account owned by the payee. Savings allotments are limited to two and must be in whole dollar amounts (no cents). The dollar amount of allotments may not exceed the pay due an employee per pay period.
If Discretionary or Third Party is checked, the specified allotment is credited to an account not owned by the payee. Certain restrictions may apply as to the kind of allotments your agency will allow. Check with your agency to determine what kinds of allotments it will allow.
Put an X in the appropriate space to indicate a checking or savings account.
Put an X in the appropriate space to indicate start/cancel/change.
Put an X in the appropriate space to indicate if an allotment is an increase, decrease and always indicate the amount.
Enter the Allottee Name, the person/company who will receive allotment.
Enter the Allottee's Routing Number, the person's/company financial institution 9-digit routing transit number, and its Check Digit.
Enter the account number to which the allotment payment will be deposited.
Enter the account holder's name on the account at the financial institution.
Enter the name of the financial institution to which the payment should be sent.
Any changes to the allotment information furnished on this request must be made using a new FASTSTART form.
More rules for Form FS 2231
Agency Use is reserved for agency use. For changes and cancellations, contact your agency for instructions.
You may also use this form to provide instructions for processing allotments and other agency-approved payments associated with your Federal employment.
Sources
[1] FS Form 2231, Department of the Treasury, Bureau of the Fiscal Service (the Official source link on this page).
