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        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS International New Discovery Fund</name>
        <lei>RC53GXLQZ5LVIZBRHR66</lei>
        <title>MFS International New Discovery Fund</title>
        <cusip>552981383</cusip>
        <identifiers>
          <isin value="US5529813835"/>
        </identifiers>
        <balance>735604.39000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>25657881.02000000</valUSD>
        <pctVal>4.045947557218</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS Research Fund</name>
        <lei>XFPOOG2XVG5TW1LZ8588</lei>
        <title>MFS Research Fund</title>
        <cusip>552981391</cusip>
        <identifiers>
          <isin value="US5529813918"/>
        </identifiers>
        <balance>515341.46000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>29219860.78000000</valUSD>
        <pctVal>4.607630078764</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS New Discovery Value Fund</name>
        <lei>LRMRW30Z8FYTIFW1W860</lei>
        <title>MFS New Discovery Value Fund</title>
        <cusip>552982696</cusip>
        <identifiers>
          <isin value="US5529826969"/>
        </identifiers>
        <balance>438777.79000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>7801469.12000000</valUSD>
        <pctVal>1.230200377972</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS Global Real Estate Fund</name>
        <lei>ROYDM6SL56ZXYAENS860</lei>
        <title>MFS Global Real Estate Fund</title>
        <cusip>552982720</cusip>
        <identifiers>
          <isin value="US5529827207"/>
        </identifiers>
        <balance>1914388.60000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>31568267.96000000</valUSD>
        <pctVal>4.977946407141</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS High Income Fund</name>
        <lei>DMVGFZCV67YA34LSI126</lei>
        <title>MFS High Income Fund</title>
        <cusip>552984684</cusip>
        <identifiers>
          <isin value="US5529846843"/>
        </identifiers>
        <balance>220226.68000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>693714.03000000</valUSD>
        <pctVal>0.109390583848</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS Growth Fund</name>
        <lei>K4ZYIH3WSXKUSPKIPM59</lei>
        <title>MFS Growth Fund</title>
        <cusip>552985673</cusip>
        <identifiers>
          <isin value="US5529856735"/>
        </identifiers>
        <balance>160870.34000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>31675369.95000000</valUSD>
        <pctVal>4.994835137527</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS Blended Research Emerging Markets Equity Fund</name>
        <lei>549300N4Y1QEM5QDU861</lei>
        <title>MFS Blended Research Emerging Markets Equity Fund</title>
        <cusip>552987240</cusip>
        <identifiers>
          <isin value="US5529872401"/>
        </identifiers>
        <balance>334359.26000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>6606939.06000000</valUSD>
        <pctVal>1.041836967349</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS Blended Research International Equity Fund</name>
        <lei>254900SJDP6D81SAVM86</lei>
        <title>MFS Blended Research International Equity Fund</title>
        <cusip>552987448</cusip>
        <identifiers>
          <isin value="US5529874480"/>
        </identifiers>
        <balance>3898200.78000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>72272642.48000000</valUSD>
        <pctVal>11.39654989699</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>MFS Mid Cap Growth Fund</name>
        <lei>XPX0WXKIO6CLKBLYF666</lei>
        <title>MFS Mid Cap Growth Fund</title>
        <cusip>552987554</cusip>
        <identifiers>
          <isin value="US5529875545"/>
        </identifiers>
        <balance>1078602.75000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>30481313.63000000</valUSD>
        <pctVal>4.806546430158</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
    </invstOrSecs>
    <explntrNotes>
      <explntrNote note="Monthly returns presented in Item B.5(a) have been calculated without deducting any applicable sales loads or redemption fees." noteItem="B.5.a"/>
    </explntrNotes>
    <signature>
      <ncom:dateSigned>2026-02-27</ncom:dateSigned>
      <ncom:nameOfApplicant>MFS SERIES TRUST XII</ncom:nameOfApplicant>
      <ncom:signature>James Byrne</ncom:signature>
      <ncom:signerName>James Byrne</ncom:signerName>
      <ncom:title>Assistant Treasurer</ncom:title>
    </signature>
  </formData>
  <documents>XXXX</documents>
</edgarSubmission>
