Lob's premium support plans are made up of a subscription payment incurred at the beginning of a chosen billing cycle (monthly or annually). Once a plan is purchased, it will renew automatically at the start of each billing cycle (monthly or yearly) unless canceled.
If you purchase a plan on the first day of the month, and elect to downgrade the next day, you will still pay for the full month. You will be entitled to what the plan offers for the entire month, even if you downgraded on the second day of the month.