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        <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 Institutional Money Market Portfolio</name>
        <lei>5L2W638H85N8T1136O07</lei>
        <title>MFS Institutional Money Market Portfolio</title>
        <cusip>55291X109</cusip>
        <identifiers>
          <isin value="US55291X1090"/>
        </identifiers>
        <balance>9732715.47000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>9734662.01000000</valUSD>
        <pctVal>1.497385159107</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 International New Discovery Fund</name>
        <lei>RC53GXLQZ5LVIZBRHR66</lei>
        <title>MFS International New Discovery Fund</title>
        <cusip>552981383</cusip>
        <identifiers>
          <isin value="US5529813835"/>
        </identifiers>
        <balance>183089.86000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>6386174.39000000</valUSD>
        <pctVal>0.982320983022</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>409805.61000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>23235978.09000000</valUSD>
        <pctVal>3.574156833958</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>267327.50000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>4753082.93000000</valUSD>
        <pctVal>0.731118947127</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 Government Securities Fund</name>
        <lei>UWWK6TDSOPDQSQMMEB12</lei>
        <title>MFS Government Securities Fund</title>
        <cusip>552982712</cusip>
        <identifiers>
          <isin value="US5529827124"/>
        </identifiers>
        <balance>7444390.03000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>64766193.30000000</valUSD>
        <pctVal>9.962332185717</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>1166716.80000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>19239160.06000000</valUSD>
        <pctVal>2.959366510921</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>8230601.84000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>25926395.78000000</valUSD>
        <pctVal>3.987996730676</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>115839.57000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>22808811.53000000</valUSD>
        <pctVal>3.508450097889</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>2181638.56000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>40447578.90000000</valUSD>
        <pctVal>6.221644295865</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>760358.40000000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>21487728.50000000</valUSD>
        <pctVal>3.305241181027</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>
