Q. When does an agency have to notify me of the tracking number assigned to my request? I know the agency can wait at least 10 days, but how long after that?

A. You are right that agencies need not assign tracking numbers to requests that will take 10 days or less to process. See 5 U.S.C. § 552(a)(7). The statute is silent, however, as to exactly when the agency must assign a request number and when it must notify the requester if a request will take longer than 10 days to process. I am not aware of a court opinion on point, nor has the Department of Justice pinpointed a deadline in any guidance.

Because an agency must provide a final determination (or seek an extension) within 20 business days, I assume that would be the latest date allowable by a court, if litigated. A number of agencies specify a time period in their regulations. The U.S. Department of Health and Human Services, for example, will “acknowledge all FOIA requests in writing within 10 working days after receipt by the appropriate office.” 45 C.F.R. § 5.24(a). And the General Services Administration, which participates in the FOIAonline system, assigns a tracking number immediately upon online receipt or no later than 2 business days. See 41 C.F.R. § 105-60.301. By contrast, the National Archives and Records Administration allows itself 20 business days to acknowledge requests. See 36 C.F.R. § 1250.26(a).