two tables:
tblCustomers :
CustID (Primary Key)
FName
LName
etc...
tblAccounts :
AcctID (Primary Key)
CustID (Foreign Key)
AcctData
etc...
Relationships :
1 - many join between tblCustomers and tblAccounts set between the CustID fields
*make sure you check referential intergrety and set cascade update and delete (so you wont have account records without customers)
HTH,
Kev