Ruling on Paying a Penalty for Delaying Payment of a Professional Association Subscription
Question

I am an engineer, and working in our field requires membership in the engineers’ association, which involves paying annual fees. I was employed in another field for five years and fell behind on my membership payments. When I sought to return to the engineering field and settle my account, I was surprised to find that I would also have to pay a late penalty. Based on my understanding of similar cases, this penalty constitutes Riba (usury). However, I do not have control over this; I must pay it if I want to continue working in my field of study. Is it permissible for me to pay this penalty, with the sin falling on those who imposed it, or should I forgo my years of study (hoping for the reward of avoiding Riba) and seek work in another field? Please note that working in this field is not possible without membership in this association, as it is mandated by state law.
Praise be to Allah.Firstly:
If a person is late in paying their association subscription, the amount due becomes a debt. As a general principle, it is forbidden to stipulate an increase on a debt, as this constitutes Riba (usury). However, there are two exceptions to this rule:

If the creditor must resort to the courts to collect the debt, they may charge the debtor for legal expenses, such as attorney fees and litigation costs.
If the currency has depreciated by one-third or more, the creditor may request compensation for the depreciation, as explained in the answer to question number 215693.

Secondly:
If you cannot renew your association membership and thus continue working in your field without paying interest on the overdue fees, it appears that doing so is permissible. This is because you were not aware of the penalty when you initially fell behind, and because paying it is necessary for you to continue working, as mandated by state law. This situation is comparable to compulsory insurance imposed by governments on properties, such as cars, which involves Riba-based commercial insurance. Scholars have permitted such payments in cases of necessity, such as when a person cannot register a vehicle without insurance. In such instances, the individual is not held accountable for the sin, as the responsibility lies with those who enforce the requirement.
Likewise, if you cannot practice in your field without paying this interest, there is no blame on you for doing so. The sin falls on those who imposed this condition.
For more details, please refer to question number 102969.
And Allah knows best.