Tolling is a legal mechanism that pauses or extends the deadline for filing a lawsuit. Common grounds for tolling include: the plaintiff was a minor when the cause of action accrued, the plaintiff was mentally incompetent, the defendant was absent from the state, fraud concealed the cause of action, or the parties entered into a written tolling agreement.
Tolling rules vary between Missouri and Illinois and depend on the specific claim type. Minor tolling, for example, generally runs the limitations period until the minor turns 18 in both states, but specific claim types have exceptions.
Tolling is a specific exception, not a general fairness principle. A court will not toll a deadline because the plaintiff didn't know the law or didn't get around to seeing a lawyer.