X0201 N-CEN/A 0001752724-18-000902 LIVE 0000783740 XXXXXXXX 811-04492 N-1A S000002511 true MFS SERIES TRUST X 811-04492 0000783740 5493001MUVNRNUPJY164 111 HUNTINGTON AVENUE 24TH FLOOR BOSTON 02199 US-MA US 617-954-5000 State Street Bank and Trust Company 1 Lincoln Street Boston 02111 617-786-3000 Custody and Accounting Records. DST Systems, Inc. 333 West 11th Street Kansas City 64105-1628 816-435-8655 Technology Vendor Institutional Shareholder Services Inc. 702 King Farm Boulevard Rockville 20850 1-301-556-0500 Proxy Voting Administrator Autonomy Americas LLC 90 Park Avenue New York 10016 44-122-344-8000 Storage Vendor Iron Mountain, Inc. 150 SE Second Street Miami 33131 N-A Storage Vendor MFS Service Center, Inc 100 Hancock Street Quincy 02171 1-617-954-5000 Transfer Agency Record TerraNua Limited (New York, NY, US, Branch) 535 Fifth Avenue New York 10017 N-A Personal Trading System The Depository Trust Company 55 Water Street New York 10041 1-212-855-1000 DTC Ropes & Gray LLP 800 Boylston Street Boston 02199-3600 1-617-951-7000 Counsel Record Massachusetts Financial Services Company 111 Huntington Avenue Boston 02199-7632 617-954-5000 Investment Adviser Record JPMorgan Chase & Co. 270 Park Avenue New York 10017-2070 1-212-270-6000 Custodian Record MFS Fund Distributors, Inc. 111 Huntington Avenue Boston 02199 1-617-954-5000 Principal Underwriter Record Y N N-1A 16 Y Maureen R. Goldfarb 000000000 N Michael Hegarty 000000000 N Robin A. Stelmach 000000000 Y Steven E. Buller 000000000 N John A. Caroselli 000000000 N John P. Kavanaugh 000000000 N Maryanne L. Roepke 000000000 N Clarence Otis, Jr. 000000000 N Robert J. Manning 000000000 Y Laurie J. Thomsen 000000000 N Martin J. Wolin 004331075 111 Huntington Avenue Boston 02199 XXXXXX N N N N N N N MFS Fund Distributors, Inc. 8-27864 000031052 0000000000 Y N Ernst & Young LLP 42 00000000000000000000 N N N N N N MFS Emerging Markets Debt Fund S000002511 509D6AOZZ4SJ08T5BZ82 Y 9 0 0 N/A N N Y N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Cash collateral reinvestment fee Revenue sharing split 3954.00000000 505.99000000 Rule 32a-4 (17 CFR 270.32a-4) Rule 12d1-1 (17 CFR 270.12d1-1) Rule 17a-7 (17 CFR 270.17a-7) Rule 22d-1 (17 CFR 270.22d-1) Y Y N N Massachusetts Financial Services Company 801-17352 000110045 1G3OSH3GLGJ7X1JC5I61 N MFS Service Center, Inc 84-1316 0000000000 Y N N Thomson Reuters Corporation 549300561UZND4C7B569 CA N Ice Data Services, Inc. 13-3668779 Tax ID N N Cititrust Colombia S A Sociedad Fiduciaria 549300242J3IJCOSGI49 CO N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Aktiengesellschaft (Mumbai, Maharashtra, IN, Branch) 0000000000 IN N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Skandinaviska Enskilda Banken A/S 0000000000 DK N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) UBS Switzerland AG 549300WOIFUSNYH0FL22 CH N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Standard Chartered Bank (Thai) Public Company Limited 549300O1LQYCQ7G1IM57 TH N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Trust Company Canada 549300L71XG2CTQ2V827 CA N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Aktiengesellschaft (Jakarta, Jakarta, ID, Branch) 0000000000 ID N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Skandinaviska Enskilda Banken AB (Oslo, Oslo, NO, Branch) F3JS33DEI6XQ4ZBPTN86 NO N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) UniCredit Bank Czech Republic and Slovakia, a.s. (Bratislava, Bratislavsky, SK, Branch) 0000000000 SK N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Citibank, National Association (Singapore, SG, Branch) E57ODZWZ7FF32TWEFA76 SG N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Stanbic IBTC Bank PLC 549300NIVXF92ZIOVW61 NG N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Aktiengesellschaft (Madrid, Madrid, ES, Branch) 529900SICIK5OVMVY186 ES N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Mizuho Bank, Ltd. (Minato ku, Tokyo, JP, Branch) RB0PEZSDGCO3JS6CEU02 JP N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Citibank del Peru S.A. MYTK5NHHP1G8TVFGT193 PE N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) UniCredit Bank Austria AG D1HEB8VEU6D9M8ZUXG17 AT N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Aktiengesellschaft (Amsterdam, Noord Holland, NL, Branch) 7LTWFZYICNSX8D621K86 NL N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Bank International GmbH ZMHGNT7ZPKZ3UFZ8EO46 DE N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Aktiengesellschaft (Makati City, Metro Manila, PH, Branch) 0000000000 PH N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Itau CorpBanca 549300DDPTTIZ06NIV06 CL N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Banco Nacional de Mexico, S. A., Integrante del Grupo Financiero Banamex. 2SFFM4FUIE05S37WFU55 MX N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Bank Handlowy w Warszawie Spolka Akcyjna XLEZHWWOI4HFQDGL4793 PL N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Hongkong and Shanghai Banking Corporation Limited (Sydney, NSW, AU, Branch) 2HI3YI5320L3RW6NJ957 AU N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Skandinaviska Enskilda Banken AB F3JS33DEI6XQ4ZBPTN86 SE N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) BNP Paribas Securities Services (Athens, Attica, GR, Branch) 549300WCGB70D06XZS54 GR N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Joint Stock Company Commercial Bank Citibank CHSQDSVI1UI96Y2SW097 RU N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) HSBC Bank Middle East Limited 549300F99IL9YJDWH369 AE N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Hongkong and Shanghai Banking Corporation Limited (Colombo, Western, LK, Branch) 0000000000 LK N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Citibank, National Association (Ciudad Autonoma de Buenos Aires, Ciudad Autonoma de Buenos Aires, AR, Branch) 579100KKDGKCFFKKF005 AR N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Hongkong and Shanghai Banking Corporation Limited (Jung-gu, Seoul, KR, Branch) 2HI3YI5320L3RW6NJ957 KR N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Bank - section 17(f)(1) (15 U.S.C. 80a-17(f)(1)) HSBC Bank Middle East Limited (Manama, Capital, BH, Branch) 0000000000 BH N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Societa per Azioni 529900SS7ZWCX82U3W60 IT N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) UniCredit Bank Hungary Zrt. Y28RT6GGYJ696PMW8T44 HU N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Standard Chartered Bank (Hong Kong) Limited X5AV1MBDXGRPX5UGMX13 HK N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Citibank, National Association (Sao Paulo, Sao Paulo, BR, Branch) 579100KKDGKCFFKKF005 BR N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) UniCredit Bank Czech Republic and Slovakia, a.s. KR6LSKV3BTSJRD41IF75 CZ N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Bank Hapoalim B.M. B6ARUI4946ST4S7WOU88 IL N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Citibank Anonim Sirketi CWZ8NZDH5SKY12Q4US31 TR N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Standard Bank of South Africa Limited QFC8ZCW3Q5PRXU1XTM60 ZA N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Hongkong and Shanghai Banking Corporation Limited (Auckland, Auckland, NZ, Branch) 2HI3YI5320L3RW6NJ957 NZ N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Hongkong and Shanghai Banking Corporation Limited (Ebene, Plaines Wilhems, MU, Branch) 0000000000 MU N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Skandinaviska Enskilda Banken AB (Helsinki, Uusimaa, FI, Branch) F3JS33DEI6XQ4ZBPTN86 FI N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Euroclear PLC 54930045L3MXWBD27H71 CH N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Citibank Maghreb S.A 5493003FVWLMBFTISI11 MA N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Bank and Trust Company (London, GB, Branch) 0000000000 GB N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Standard Chartered Bank Malaysia Berhad 549300JTJBG2QBI8KD48 MY N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) N MFS Service Center, Inc 0000000000 Y N N Massachusetts Financial Services Company 1G3OSH3GLGJ7X1JC5I61 Y N N Merrill Lynch, Pierce, Fenner & Smith Incorporated 8-7221 000007691 8NAV47T0Y26Q87Y0QP81 32947.47000000 32947.47000000 Goldman Sachs & Co. LLC 8-129 000000361 FOR8UP27PHTHYVLBNG30 721617869.10000000 Bank Of America Merrill Lynch Securities Inc 8-33359 000016139 0000000000 1330593551.00000000 JPMorgan Chase & Co. 8-35008 000000079 8I5DZWZKVSZI1NUHU748 1494962269.00000000 Deutsche Bank Securities Inc. 8-17822 000002525 9J6MBOOO7BECTDTUZW19 704696278.90000000 BNP Paribas Securities Corp. 8-32682 000015794 RCNB6OTYUAMMP879YW96 626021978.00000000 Jefferies LLC 8-15074 000002347 58PU97L1C0WSRCWADL48 738047390.10000000 HSBC Securities (USA) Inc. 8-41562 000019585 CYYGQCGNHMHPSMRL3R97 1161531205.00000000 Citigroup Global Markets Inc. 8-8177 000007059 MBNUM2BPBDO7JBLYG310 1751073005.00000000 Barclays Capital Inc. 8-41342 000019714 AC28XWWI3WIBK2824319 727333285.50000000 Morgan Stanley & Co. LLC 8-15869 000008209 9R7GPTSO7KV3UQJZQ078 448617822.60000000 12327522594.42000000 N 6221443725.00000000 N true