What is the ruling of Islamic law regarding price offers that stipulate payment after 90 days, with the possibility of obtaining a 2% discount for early cash payment, and what is the legitimate alternative to such types of sales if they are impermissible?

If the discount percentage is deducted at the time of the sales contract with companies, such that the contract is made for ninety-eight percent of the market value of the commodity, then there is no harm in that. However, if a contract is made for a specific price and then the buyer wishes to expedite payment to benefit from a discount, this is not permissible according to the majority of scholars. This is known by the rule "give less (in debt) and I will pay you sooner." This is because expediting payment for what is owed is considered a loan, and every loan that brings a benefit is usury (riba). The Shariah-compliant alternative is to contract for immediate payment so that the percentage is discounted at the time of the sales contract.