where field B is duplicated and field K is not null (SQL)

better post sample data and identify which records you don't want to see.

attached is some sample data.
as you'll notice the second field (Account) is the same for the last two records.  However only the second last record has a comment of "PRIMARY PIN SAME AS SPOUSE PIN".  This record I don't want to see.

Note that another record also has "PRIMARY PIN SAME AS SPOUSE PIN" as a comment, but the ACCOUNT is not duplicated, therefore I would still like to see this record.

Company	Account	ID	PIN	Received	First Name	Last Name	Status	Joint PIN	Spouse Name	Spouse PIN	Comment
HAL	PH399PBL	1P8P93U	9911UU98P	I	xxx	yyy	A	9928U9335	xxx yyy		
HAL	PJ1157AL	1P8PU19	9U298995U	I	xxx	yyy	A	9U8911UU5	xxx yyy		
HAL	PJ5528AL	1P89198	11UU7U359	I	xxx	yyy	A		xxx yyy	11UU7U359	PRIMARY PIN SAME AS SPOUSE PIN
HAL	PJ1532AL	1P8P915	115789P7U	I	xxx	yyy	L	1127U5193	xxx yyy		
HAL	PJ1533AL	1P8P915	115789P7U	I	xxx	yyy	L	1127U5193	xxx yyy		
HAL	PJ159UAL	1P8P97P	11U3829P9	I	xxx	yyy	A		xxx yyy	1215P5U71	
HAL	PJ1739AL	1P81P81	9P89U2181	I	xxx	yyy	A	93755P259	xxx yyy		
HAL	PJ18U2AL	1P81187	9379P9311	I	xxx	yyy	L		xxx yyy	9379P9311	PRIMARY PIN SAME AS SPOUSE PIN
HAL	PJ18U2AL	1P81187	9379P9311	I	xxx	yyy	L		xxx yyy	92U231932	

Select allOpen in new window

If you paste the above sample in Excel as TEXT it will delimit properly into each column.

select *
from tableX
where [Account ID] not in(select [Account ID] from TableX as A where tableX.[Spouse PIN] <>null)

for some reason that always returns no records.
if I use In instead of Not In (without checking Column K), I get all the records as expected.  If the subquery is just  Not In (select [Account ID] from temp as A) .. it still doesn't return anything.

post the sql of the query you are using