What is the ruling on agreeing with a customs clearance agent on a lump sum for clearing goods, such that the importer has no relation to any increase or decrease in the actual cost of customs expenses, handling, and transport?

The dealings between you and the customs broker fall into two categories:

First Case: If the customs broker possesses influence (authority or intercession) with the entity they are dealing with, then it is permissible for them to receive a customary wage (اجرة المثل) in exchange for their influence, provided that this requires expenditure, effort, or travel, and does not infringe upon the rights of others. This is the more preponderant opinion. The wage can be known or unknown if the transaction is based on mutual leniency.

Second Case: If the customs broker does not possess influence, and is merely a person who follows up on transactions due to their skill in doing so, then the transaction in the aforementioned manner is invalid according to the majority of jurists, due to the unknown nature of the wage. In this case, the worker is entitled to a customary wage after deducting the expenses they incurred.