43 CFR §3275.17

1. (a)If you find an error in a meter used to calculate Federal royalty, you must correct the error immediately and notify BLM by the next working day of its discovery.
2. (b)If the meter is not used to calculate Federal royalty, you must correct the error and notify us within 3 working days after its discovery.
3. (c)If correcting the error will cause a change in the sales quantity of more than 2 percent for the month(s) in which the error occurred, you must adjust the sales quantity for that month(s) and submit an amended facility report to us within 3 working days.