INSERT/UPDATE TRIGGER error

CREATE OR REPLACE TRIGGER cust_trig_iu
AFTER insert or update on CUST
For each row
BEGIN
IF INSERTING then
INSERT into CUST_INTERFACE (
c_id,f_name,mi,l_name,inst_id,pay_freq,lookup2,lookup3,action_code,insert_type,time_stamp)
VALUES (:new.c_id,:new.f_name,:new.mi,:new.l_name,:new.inst_id,:new.pay_freq,:new.lookup2,:new.lookup3,:new .action_code,
'I',to_char(sysdate,'DD-MON-YY HH24:MM:SS'));
ELSE
INSERT into CUST_INTERFACE (
c_id,f_name,mi,l_name,inst_id,pay_freq,lookup2,lookup3,action_code,insert_type,time_stamp)
VALUES (
:new.c_id,:new.inst_id,:new.f_name,:new.mi,:new.l_name,:new.pay_freq,:new.lookup2,:new.lookup3,:new. action_code,
'U',to_char(sysdate,'DD-MON-YY HH24:MM:SS'));
END IF;
END;

The trigger created quite alright without errors but when
I insert or update on the cust table, I get the following errors:
ora-01401: insert value too large for column (which is not true)
ora-06512: at webuser, cust_tri_iu line 28
ora-04088: error during execution of trigger

I appreciate your input please:

compare length all fields in declaration both tables:
desc CUST ;
desc CUST_INTERFACE ;

one or more fields in CUST_INTERFACE have less length then in CUST table.

I have checked, all the columns from both tables have equal length and datatype.
Thank you.

Next :
check field - time_stamp - it should be no less then VARCHAR2(18) or CHAR(18)

I used VARCHAR2(25) for time_stamp, still when I update cust table for instance, it gives the following errors:

SQL> update cust
2 set cust_id=6914
3 where pin='8822';
update cust
*
ERROR at line 1:
ORA-01401: inserted value too large for column
ORA-06512: at "WEBUSER.CUST_TRIG_IU", line 28
ORA-04088: error during execution of trigger 'WEBUSER.CUST_TRIG_IU'

If u may, post to forum describe statments of both tables.
desc CUST ;
desc CUST_INTERFACE ;

Hi

Surely there is no problem with the time_stamp column but there is a mismatch with the datatype and width with one of the column.Try using the trim function in your insert statement because char embeds spaces whereas varchar does not.if there is still a problem desc the table in the forum as said

Regards