Error at rollback transaction line

Error appears when I uncomment Rollback transaction line after OutputID=-1

I want to rollback the transaction if any of the serial number is not matching for a particular OrderID.

Can you please help me where am i going wrong with the transactions. Begin and Commit Statements looks fine for me.Verified all the begin commit statements through out the proc

ALTER PROC dbo.UpdatePartnerSerialNumbersBatchDetails
  @OrderID             INT
, @SerialNumberDetails XML = NULL
, @SerialNumbersCount  INT
, @UploadedBy          VARCHAR(50)
, @UploadedDate        DATETIME
, @OutputID            INT OUT
AS
BEGIN
  
  SET XACT_ABORT, NOCOUNT ON;

  BEGIN TRY
    DECLARE @BatchCount INT;

    IF @SerialNumbersCount <> (SELECT TOP 1
                                      OrderQty
                               FROM   OrderMaster
                               WHERE  OrderID = @OrderID
                                      AND IsDeleted = 0)
    BEGIN
      SET @OutputID = -2;    
    END;
    ELSE
    BEGIN
      BEGIN TRANSACTION SerialNumbers;

      UPDATE
            dbo.PartnerSerialNumbers
      SET
            BatchNo = T.N.value('(BatchNo/text())[1]', 'varchar(50)')
          , DataUploadfromPartner = 1
          , ExpiryDate = T.N.value('(ExpiryDate/text())[1]', 'Datetime')
          , SerialNoStatus = 'O'
          , UploadedBy = @UploadedBy
          , UploadedDate = @UploadedDate
      FROM  @SerialNumberDetails.nodes('Root/SerialNumberDetails') AS T(N)
      WHERE OrderID = @OrderID
            AND SerialNo = T.N.value('(SerialNumber/text())[1]', 'varchar(50)');

      SET @BatchCount = @@ROWCOUNT;

      IF @BatchCount <> (SELECT TOP 1
                                OrderQty
                         FROM   OrderMaster
                         WHERE  OrderID = @OrderID
                                AND IsDeleted = 0)
      BEGIN
       
        SET @OutputID = -1;    
        ROLLBACK TRANSACTION SerialNumbers;
      END;
      ELSE
      BEGIN
        SET @OutputID = 1;

        UPDATE
              OrderMaster
        SET
              DataUploadfromPartner = 1
        WHERE OrderID = @OrderID;

        INSERT INTO SerialnumbersLogDetails
          (
            OrderID
          , SerialNo
          , GTINCode
          , OrderSentDate
          , OrderorPartner
          , BatchNo
          , ExpiryDate
          )
        SELECT
              OrderID
            , SerialNo
            , GTINCode
            , NULL
            , 'Partner'
            , BatchNo
            , ExpiryDate
        FROM  PartnerSerialNumbers
        WHERE OrderID = @OrderID;
      END;

      
      COMMIT TRANSACTION SerialNumbers;
    END;
  END TRY
  BEGIN CATCH    
    SET @OutputID = 0;

    IF @@trancount > 0 ROLLBACK TRANSACTION SerialNumbers;
  END CATCH;
END;

BEGIN
       
        SET @OutputID = -1;    
       -- ROLLBACK TRANSACTION SerialNumbers;
      END;