SQL Server 2017

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Microsoft SQL Server 2017 (RTM-CU21) (KB4557397) - 14.0.3335.7 (X64) 
	Jun 12 2020 20:39:00 
	Copyright (C) 2017 Microsoft Corporation
	Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)



Create Table #Data
(
    CustomerCode varchar(50),
    Frequency varchar(50) NULL,
    Type varchar(50) NULL,
    TypeAmount money NULL
)

insert into #Data
(
    CustomerCode,
    Frequency,
    Type,
    TypeAmount 
)
select
    'C12345',
    'Monthly',
    NULL,
    NULL
union all
select
    'C12345',
    NULL,
    'A1',
    '5.00'
union all
select
    'C12345',
    NULL,
    'A2',
    '20.00'
union all
select
    'C12345',
    'Fornightly',
    NULL,
    NULL
union all
select
    'C12345',
    NULL,
    'A1',
    '5.00'
union all
select
    'C12345',
    NULL,
    'A2',
    '20.00'
union all
select
    'C56789',
    'Fornightly',
    NULL,
    NULL
union all
select
    'C56789',
    NULL,
    'A1',
    '50.00'
8 rows affected

select * from #data


CustomerCode
Frequency
Type
TypeAmount


C12345
Monthly
null
null

C12345
null
A1
5.0000

C12345
null
A2
20.0000

C12345
Fornightly
null
null

C12345
null
A1
5.0000

C12345
null
A2
20.0000

C56789
Fornightly
null
null

C56789
null
A1
50.0000


With cte AS
(
SELECT customerCode, frequency, type, TypeAmount, rn
FROM 
    (
     SELECT *, ROW_NUMBER()OVER(PARTITION BY CustomerCode ORDER BY CustomerCode) AS rn
     FROM #data
    ) AS d
WHERE Frequency IS NOT NULL

UNION ALL

SELECT d2.customerCode, cte.frequency, d2.type, d2.TypeAmount, d2.rn
From 
     (
      SELECT *, ROW_NUMBER()OVER(PARTITION BY CustomerCode ORDER BY CustomerCode) AS rn
      FROM #data
     ) AS d2
INNER JOIN cte
  ON d2.rn=cte.rn+1
  AND d2.CustomerCode=cte.CustomerCode
WHERE d2.Frequency IS NULL
)

SELECT * 
FROM cte 
WHERE Type IS NOT NULL 
  AND TypeAmount IS NOT NULL
ORDER BY CustomerCode, rn;


customerCode
frequency
type
TypeAmount
rn


C12345
Monthly
A1
5.0000
2

C12345
Monthly
A2
20.0000
3

C12345
Fornightly
A1
5.0000
5

C12345
Fornightly
A2
20.0000
6

C56789
Fornightly
A1
50.0000
2

CustomerCode	Frequency	Type	TypeAmount
C12345	Monthly	null	null
C12345	null	A1	5.0000
C12345	null	A2	20.0000
C12345	Fornightly	null	null
C12345	null	A1	5.0000
C12345	null	A2	20.0000
C56789	Fornightly	null	null
C56789	null	A1	50.0000