From the discussion of damaged cash exchange transactions carried out by corrupted money collectors in the city of Medan, the author can draw several conclusions, as follows: Currency transactions that are unfit for circulation that occur in the city of Medan are closely related to the concept of the sharf contract in the perspective of Islamic economic law. This is, if we look at it from the object being transacted, namely currency, even though the money is money which is not fit for circulation. In this transaction, the terms and conditions in the sharf contract concept must be fulfilled in it. The application of Law of the Republic of Indonesia Number 7 of 2011 concerning Money Changes in the community has been running, but is still not optimal. This is because there are still many people who do not know or do not understand how to exchange their damaged cash. Most people feel that the damaged cash they have is no longer sold to be spent. In fact, based on the Regulation of Members of the Board of Governors Number 19/13 / PDADG / 2017 concerning Rupiah Currency Exchange, it explains the procedure for exchanging money that is not fit for circulation. In the perspective of Islamic economic law, the practice of changing corrupted money by the corrupt money-seeking community is divided into three opinions. One opinion says, it is legally forbidden'. This opinion argues that the laws that apply to paper money also apply to gold and silver. There are two requirements in the sale and purchase of gold with gold or silver and silver, namely: the same weights and cash in one agreement. Meanwhile, the second opinion is allowed even though there is a difference in the nominal value. Another case is the third opinion which first sees the public's attitude towards money unfit for circulation.

This study aims to find the problems and strategies carried out by the Lazis Muhammadiyah management in Medan are divided into two, namely internal and external. And what is being done is an effort to raise awareness together to channel zakat al-mal to Lazis Muhammadiyah so that it is managed properly and transparently and evenly so that it directly touches the community so that the objectives of the zakat law are realized. Management of zakat based on Law Number 23 of 2011 is zakat management states that zakat management aims to increase the effectiveness and efficiency of services in managing zakat; and increase the benefits of zakat to create social welfare and poverty alleviation. Efforts to realize the function and role of zakat in the welfare of society, the zakat management law issued by the government is in principle to facilitate, motivate and confirm the management of zakat issued by the Amil Zakat Agency or the Amil Zakat Institute.