Some people generally feel so uncomfortable when they have to write a request letter to their boss. In some cases, the person can also use his payslip to prove that he is an experienced person since the job tenure is also mentioned in this document.When there are some discounts and benefits for the person salary of whom lies in the specific range and that person wants to avail that, he can submit his certificate of pay.For instance, while applying for a loan, the salary certificate is generally needed. When a person has to prove that he is employed and is capable of managing his finances.There are many situations in which, this document is generally needed. However, when a person has to show his income somewhere, he completely relies on the salary slip that the company where he works issues him. This income is generally documented at various places and in various databases. People who are not self-employed work for some other people in exchange for a monthly income.