Report of Independent Auditors
To the Trustees
MFS Series Trust X
In planning and performing our audits of the financial statements of MFS
Emerging Markets Equity Fund, MFS International Growth Fund and MFS
International Growth and Income Fund ("the funds"), three of the funds
comprising MFS Series X, for the year ended May 31, 2000, we considered its
internal control, including control activities for safeguarding securities, to
determine our auditing procedures for the purpose of expressing our opinion on
the financial statements and to comply with the requirements of Form N-SAR, and
not to provide assurance on internal control.
The management of the Trust is responsible for establishing and maintaining
internal control. In fulfilling this responsibility, estimates and judgments by
management are required to assess the expected benefits and related costs of
internal control. Generally, internal controls that are relevant to an audit
pertain to the Trust's objective of preparing financial statements for external
purposes that are fairly presented in conformity with generally accepted
accounting principles. Those internal controls include the safeguarding of
assets against unauthorized acquisition, use, or disposition.
Because of inherent limitations in any internal control, misstatements due to
errors or fraud may occur and not be detected. Also, projections of any
evaluation of internal control to future periods are subject to the risk that
internal control may become inadequate because of changes in conditions, or that
the degree of compliance with the policies or procedures may deteriorate.
Our consideration of internal control would not necessarily disclose all matters
in internal control that might be material weaknesses under standards
established by the American Institute of Certified Public Accountants. A
material weakness is a condition in which the design or operation of one or more
of the specific internal control components does not reduce to a relatively low
level the risk that errors or fraud in amounts that would be material in
relation to the consolidated financial statements being audited may occur and
not be detected within a timely period by employees in the normal course of
performing their assigned functions. However, we noted no matters involving
internal control, including control activities for safeguarding securities, and
its operation that we consider to be material weaknesses as defined above at May
31, 2000.
This report is intended solely for the information and use of the board of
trustees and management of MFS Series Trust X and the Securities and Exchange
Commission and is not intended to be and should not be used by anyone other than
these specified parties.
Ernst & Young LLP
July 7, 2000
