10.27—Fees.
        
        (a) In general.
         A practitioner
 may not charge an unconscionable fee in connection
 with any matter before the Internal Revenue
 Service.
    
    
        
        (b) Contingent fees—
        
        (1) 
         Except as
provided in paragraphs (b)(2), (3), and (4) of
this section, a practitioner may not charge a
contingent fee for services rendered in connection
with any matter before the Internal Revenue
Service.
    
    
        
        (2) 
         A practitioner may charge a contingent fee
 for services rendered in connection with the
 Service's examination of, or challenge to—
    
    
    
        
        (ii) 
         An amended return or claim for refund or
 credit where the amended return or claim for
 refund or credit was filed within 120 days of the
 taxpayer receiving a written notice of the
 examination of, or a written challenge to the
 original tax return.
    
    
        
        (3) 
         A practitioner may charge a contingent fee
 for services rendered in connection with a claim
 for credit or refund filed solely in connection
 with the determination of statutory interest or
 penalties assessed by the Internal Revenue
 Service.
    
    
        
        (4) 
         A practitioner may charge a contingent fee
 for services rendered in connection with any
 judicial proceeding arising under the Internal
 Revenue Code.
    
    
    
        
        (1) 
        
            Contingent fee is any fee
 that is based, in whole or in part, on whether or
 not a position taken on a tax return or other
 filing avoids challenge by the Internal Revenue
 Service or is sustained either by the Internal
 Revenue Service or in litigation. A contingent fee
 includes a fee that is based on a percentage of
 the refund reported on a return, that is based on
 a percentage of the taxes saved, or that otherwise
 depends on the specific result attained. A
 contingent fee also includes any fee arrangement
 in which the practitioner will reimburse the
 client for all or a portion of the client's fee in
 the event that a position taken on a tax return or
 other filing is challenged by the Internal Revenue
 Service or is not sustained, whether pursuant to
 an indemnity agreement, a guarantee, rescission
 rights, or any other arrangement with a similar
 effect.
    
    
        
        (2) 
        
            Matter before the Internal
 Revenue Service includes tax planning and
 advice, preparing or filing or assisting in
 preparing or filing returns or claims for refund
 or credit, and all matters connected with a
 presentation to the Internal Revenue Service or
 any of its officers or employees relating to a
 taxpayer's rights, privileges, or liabilities
 under laws or regulations administered by the
 Internal Revenue Service. Such presentations
 include, but are not limited to, preparing and
 filing documents, corresponding and communicating
 with the Internal Revenue Service, rendering
 written advice with respect to any entity,
 transaction, plan or arrangement, and representing
 a client at conferences, hearings, and
 meetings.
    
    
        
        (d) Effective/applicability date.
         
 This section is applicable for fee arrangements
 entered into after March 26, 2008.