How were mercenary companies retained for battle?

How did a medieval employer keep a mercenary company after its contract or pay ran out?

Continued pay was essential, but a king could also knight a successful captain and increase the status and troop types available to his company.

A viewer jokingly asks whether mercenary companies received reminders before their contracts expired. Payment was the practical reminder: if the money stopped, a company could be gone the next day. A king facing battle might instead retain a valuable captain through knighthood, which let him attract impoverished knights and squires as well as archers and men-at-arms. Cash, status, and patronage combined to assemble a flexible professional force.