28 CFR Part 36, Appendix C: Guidance on ADA Regulation on Nondiscrimination on the Basis of Disability by Public Accommodations and in Commercial Facilities (2010 ADA Title III Regulations: 1991 Preamble and Section-by-Section Analysis)

"Undue burden.'' The definition of "undue burden'' is analogous to the statutory definition of "undue hardship'' in employment under section 101(10) of the ADA. The term undue burden means "significant difficulty or expense'' and serves as a limitation on the obligation to provide auxiliary aids and services under Sec.36.303 and Sec. 36.309 (b)(3) and (c)(3). Further discussion of the meaning and application of the term undue burden may be found in the preamble discussion of Sec.36.303.

The definition lists factors considered in determining whether provision of an auxiliary aid or service in any particular circumstance would result in an undue burden. The factors to be considered in determining whether an action would result in an undue burden are identical to those to be considered in determining whether an action is readily achievable. However, "readily achievable'' is a lower standard than "undue burden'' in that it requires a lower level of effort on the part of the public accommodation (see Education and Labor report at 109).

Further analysis of the factors to be considered in determining undue burden may be found in the preamble discussion of the definition of the term "readily achievable.''