It is an unsaid rule in the world of loans that one needs a co-signer to ensure that the student loan gets approved. That said, it does not mean that you would not get loans if you do not have a co-signer to sign on your agreement. There are some lenders in the market who would offer loans to you with you having to worry about the co-signer.
Loan agreements, like any contract, reflect an "offer," the "acceptance of the offer," "consideration," and can only involve situations that are "legal" (a term loan agreement involving heroin drug sales is not "legal"). Loan agreements are documented via their commitment letters, agreements that reflect the understandings reached between the involved parties, a promissory note, and a collateral agreement (such as a mortgage or a personal guarantee). Loan agreements offered by regulated banks are different from those that are offered by finance companies in that banks receive a "banking charter" granted as a privilege and involving the "public trust."
Borrowers should create a folder to store loan document records, along with a record of phone and email correspondence. Always keep track of phone conversations by writing down a summary of the call, date, time, and name of the bank representative spoken with. When important documents are mailed, invest in the extra protection of tracking receipts. Certified letters should be sent with a return receipt request in case it is necessary to provide evidence the documents were received.
Lenders may require borrowers to submit a financial letter of hardship which explains the circumstances causing them to require a loan deferment. Hardship letters are usually required with federal student loans and real estate transactions such as loan modifications.