Former Speakers of the House: Office Allowances, Franking Privileges, and Staff Assistance [May 14, 2014] [open pdf - 213KB]
"Since 1970, former Speakers of the House of Representatives have been provided with an allowance after their departure from the House. Currently, the statutorily authorized allowance is available to former Speakers for office space and furnishings, office operations, franked mail, and staff assistance. Use of the allowance is limited to five years, beginning the day of expiration of a Speaker's tenure as a Representative. Allowances are to be used solely for the administration and conclusion of matters relating to service as a Representative and Speaker of the House."
CRS Report for Congress, RS20099