Final answer:
A customer's downgrade typically takes effect at the end of the current billing cycle, allowing them to use their current plan's features until then, after which they will transition to the lower-tier plan.
Step-by-step explanation:
When a customer chooses to downgrade their service rather than cancel, the timing of when the downgrade takes effect usually depends on the company's policy. Generally, the downgrade will take effect at the end of the current billing cycle. This means that the customer will continue to have access to the features of their current plan until the cycle ends. After that, their service will switch to the lower-tier plan and they will be billed accordingly.