The mitzvah of shmittas kesofim, the annulment of all debts, is a rabbinical mitzvah nowadays and applies both in Eretz Yisroel as well as in Chutz La’aretz. During the year of shmittah, all previous debts are cancelled. When Chazal saw that due to the observance of shmittas kesofim people were reluctant to lend money with the approach of the shmittah year, and were thus violating the mitzvah of "Hishomer lecho pen yihye dovor im lvovcho bliyaal", deciding not to lend money to people due to the concern that the debts will be cancelled, they instituted the concept of pruzbul. Pruzbul is a legal mechanism through which one gives over the debts they are owed to the Beis Din, who can then collect them on the lender’s behalf at any time. Thus, a pruzbul would enable a lender to collect their debts even after the year of shmittah. Pruzbul is a very easy process to perform. According to most poskim, one has to approach three people and tell them a particular nusach, prepared text, implying that the debts are given over to a Beis Din, after which they can be collected at any time. This applies to both men and women, and according to the Alter Rebbe and many other poskim it should be done before the shmittah year, which begins this upcoming Rosh Hashana. The best time to make a pruzbul is on Erev Rosh Hashana directly after Hatoras Nedorim. If someone cannot find three people, they can always do a shtar pruzbul, a written pruzbul, and give or send it to the Beis Din.