Every Rate Card row has a Rate Period that tells the system what the rate dollar amount actually represents. There are four options.
Per Month — the rate is what you charge per unit per calendar month. This is the most common option in the industry and the default for new rows. If you set $85 per unit per month with 4 units, you bill $340 per month for that site.
Per 28-Day Cycle — the rate is what you charge per unit per 28-day cycle. There are 13 cycles in a year (instead of 12 months), so a 28-day rate generates slightly more annual revenue than the same monthly rate. Many established operators bill on 28-day cycles because four weekly service visits map cleanly to one billing cycle. If you set $85 per unit per 28-day cycle with 4 units, you bill $340 per cycle, 13 times a year.
Per Week — the rate is what you charge per unit per week. Less common for portable sanitation, but available if you have weekly-billed customers.
Flat (one-time) — the rate is a one-time charge per unit, not tied to a recurring period. Used for special arrangements, deposits, or one-off line items. Flat-rate locations are excluded from MRR calculations because they aren't recurring.
The Billing Summary shows a Cycle Value column — the dollar amount that row bills per cycle, matching what the invoice actually charges. For MRR, that per-cycle amount is normalized to a monthly equivalent behind the scenes so the total is comparable: Monthly is 1x, Per 28-Day is 13/12 (~1.083x), Weekly is 4.33x, Flat is excluded. This lets you mix periods across customers and still have a meaningful recurring revenue number at the bottom.
The customer's billing cycle (set on their profile) determines when invoices roll up. If the customer's billing cycle and the location's rate period match exactly (28-day customer with per-28-day location, monthly customer with per-month location), the line item charges the rate directly. If they mismatch, the system normalizes to keep the charge honest.