DIFFERENCE BETWEEN PASSIVE SOLIDARITY (SOLIDARITY AMONG DEBTORS) AND SURETYSHIP

The two are SIMILAR in the following ways: 

1.  A  solidary  debtor,  like  a  surety,  STANDS  FOR  SOME  OTHER PERSON. 
2.  Both  debtor  and  surety, after payment, may require that they be REIMBURSED. 
 
The  difference  is  that  the  lender  cannot  go  after  the  surety  right away.  There has to be default on the part of the principal debtor before the surety becomes liable.  If it were mere solidarity among debtors,  the  creditor  can  go  after  any  of  the  solidary  debtors  on due date.