Answered by Shaykh Abdurrahman ibn Yusuf Mangera
We have a clothing store in America and we rent it out from the shopping Mall for $1700 dollars a month. It is written in the contract that we did with them that we have to give them an additional 15% of what we sell if we sell over $17,000 a month. The percentage is for the amount that is after the $17,000. Do we have to give them this percentage? We have not given them this percentage for a while. Do they deserve this percentage since they did not put in money in the business and the percentage is indefinite.
Assalamu alaykum
This is not a permissible contract, since they are not a partner in your business. Your agreement with the landlord is one of rent in which case the rent amount needs to be fixed. You need to renegotiate with the landlord on different terms and should not enter into any contract that contravenes the laws of Islam in the first place.
Renegotiate your contract with the landlord on absolute terms. If he wants, he may initially sign a three or four months contract and then renegotiate the rent at a higher amount if the business does better.
And Allah knows best.
Wassalam
Abdurrahman ibn Yusuf