WITH Unpivotted (ZIPCODEFROM ,ZIPCODETO,Value,Name) AS (
SELECT ZIPCODEFROM ,NULL,'start','ID'
FROM dbo.Mileage
WHERE ZIPCODEFROM IS NOT NULL

UNION ALL

SELECT ZIPCODEFROM ,NULL,'Start','NAME'
FROM dbo.Mileage
WHERE ZIPCODEFROM IS NOT NULL

UNION ALL

SELECT ZIPCODEFROM ,NULL,'1','RIGIDACC'
FROM dbo.Mileage
WHERE ZIPCODEFROM IS NOT NULL

UNION ALL

SELECT NULL ,ZIPCODETO,'end','ID'
FROM dbo.Mileage
WHERE ZIPCODETO IS NOT NULL

UNION ALL

SELECT NULL ,ZIPCODETO,'End','NAME'
FROM dbo.Mileage
WHERE ZIPCODETO IS NOT NULL

UNION ALL

SELECT ZIPCODEFROM ,NULL,ZIPCODEFROM,'POSTCODE'
FROM dbo.Mileage
WHERE ZIPCODEFROM IS NOT NULL

UNION ALL

SELECT NULL ,ZIPCODETO,ZIPCODETO,'POSTCODE'
FROM dbo.Mileage
WHERE ZIPCODETO IS NOT NULL

)
SELECT 'DEPOT' AS "@ObjectType",
       (SELECT a.Name AS "@KeywordName",
               a.Value AS "text()"
        FROM Unpivotted a
        WHERE a.ZIPCODEFROM=b.ZIPCODEFROM
        FOR XML PATH('Value'), ROOT('Object'), TYPE)
FROM dbo.Mileage b
WHERE b.ZIPCODEFROM<>''

UNION ALL

SELECT 'CUST' AS "@ObjectType",
       (SELECT a.Name AS "@KeywordName",
               a.Value AS "text()"
        FROM Unpivotted a
        WHERE a.ZIPCODETO=b.ZIPCODETO
        FOR XML PATH('Value'), ROOT('Object'), TYPE)
FROM dbo.Mileage b
WHERE b.ZIPCODETO<>''
FOR XML PATH('ObjectSequence'), ROOT('SupplierData'), TYPE;

<SupplierData>
  <ObjectSequence ObjectType="DEPOT">
    <Object>
      <Value KeywordName="ID">start</Value>
      <Value KeywordName="NAME">Start</Value>
      <Value KeywordName="RIGIDACC">1</Value>
      <Value KeywordName="POSTCODE">XX37 9</Value>
    </Object>
  </ObjectSequence>
  <ObjectSequence ObjectType="CUST">
    <Object>
      <Value KeywordName="ID">end</Value>
      <Value KeywordName="NAME">End</Value>
      <Value KeywordName="POSTCODE">ZZ12 4</Value>
    </Object>  
  </ObjectSequence>
</SupplierData>