SQL Server 2022

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--Create test table.
CREATE TABLE charges (
  meter_id int
  , contract_number int 
  , charge_amt decimal(19,2)
  , invoice_number int
  , MPAN_number nvarchar(100)
  , charge_date date
);

--Insert test data.
INSERT INTO charges (
  meter_id, contract_number, charge_amt, invoice_number, MPAN_number
  , charge_date)
VALUES 
 (123, 998, 25.54, 3216549, '123AM234ASF', '1/2/2022')
 , (456, 12399, 25.54, 3216668, '123AM234ASF', '1/15/2022')
 , (987, 887, 25.54, 3589765, 'K18D01652', '1/5/2022')
 , (654, 123488, 25.54, 3548892, 'K18D01652', '1/28/2022')
;

--For debugging, show all test data.
SELECT * FROM charges;

--Use a CTE to add a row_num column. 
--This row_num column will sequence "duplicate" charge lines by charge_date with the most recent charge as row_num = 1.
--The common data in the example data is the MPAN_number.
--This is only an example, for more specific help, you need to create
--a mimimal reproducible example just like this.
WITH prelim as (
  SELECT *, ROW_NUMBER() OVER(PARTITION BY MPAN_number ORDER BY charge_date DESC) as row_num
  FROM charges
)
SELECT *
FROM prelim
WHERE row_num = 1
;

--Here's an example of how to delete all "duplicate" charges that are not the most recent charge.
DELETE c 
FROM charges as c
  INNER JOIN (
    SELECT *, ROW_NUMBER() OVER(PARTITION BY MPAN_number ORDER BY charge_date DESC) as row_num
    FROM charges
  ) as oldDups
    ON oldDups.MPAN_number = c.MPAN_number
    AND oldDups.meter_id = c.meter_id
    AND oldDups.contract_number = c.contract_number
    AND oldDups.row_num <> 1
;

--For debugging, show the test data after deletions.
SELECT * FROM charges;

meter_id	contract_number	charge_amt	invoice_number	MPAN_number	charge_date
123	998	25.54	3216549	123AM234ASF	2022-01-02
456	12399	25.54	3216668	123AM234ASF	2022-01-15
987	887	25.54	3589765	K18D01652	2022-01-05
654	123488	25.54	3548892	K18D01652	2022-01-28

meter_id	contract_number	charge_amt	invoice_number	MPAN_number	charge_date	row_num
456	12399	25.54	3216668	123AM234ASF	2022-01-15	1
654	123488	25.54	3548892	K18D01652	2022-01-28	1

meter_id	contract_number	charge_amt	invoice_number	MPAN_number	charge_date
456	12399	25.54	3216668	123AM234ASF	2022-01-15
654	123488	25.54	3548892	K18D01652	2022-01-28