PRIVATE, BROWSER-ONLY WORKSHEET · Personal Money
Subscription Billing Interval Audit
Review named subscriptions against approximate next billing dates from their last bill and cadence, with overdue estimates flagged in a table.
A monthly subscription last billed on 2026-09-01 has an estimated next date of 2026-10-01 using the 30-day convention.
Set up the calculation
Enter amounts in one currency, or load the worked example. Your entries stay in this browser.
Your result
Subscriptions due for review
UNDERSTAND THE RESULT
How to use the Subscription Billing Interval Audit
Use this to scan a short list of recurring services and identify dates to check against provider accounts before another charge arrives.
What to enter
For each unique subscription enter the charged amount, actual last billing date in YYYY-MM-DD form, and a supported cadence. Choose the review date separately.
Worked example
A monthly subscription last billed on 2026-09-01 has an estimated next date of 2026-10-01 using the 30-day convention.
How to read the result
Review overdue means the estimated interval has elapsed. It does not prove a charge occurred or that the account is unpaid; verify with the provider.
Method
Add 7, 30, 91, or 365 days to each last-bill date for weekly, monthly, quarterly, or yearly cadence, then compare that estimate with the review date.
What to check
Month and year lengths vary; these are estimates, not provider renewal dates. Trials, grace periods, failed payments, taxes, and invoice rules are excluded.
Avoid this mistake
Assuming a 30-day monthly estimate exactly matches a calendar-month renewal, especially around February or a 31-day month.
Calculations run locally in your browser. No entered values are sent to the Nirmion API.
Questions to check
Why are dates approximate?
Monthly and yearly provider rules differ; this tool uses fixed day intervals stated in the method.
Does overdue mean unpaid?
No. It only means the estimated next-bill date is on or before the review date.
Can it cancel a plan?
No. Changes must be made with the provider.