Your company has 15 business days from the formal date of issuance to respond to the 483. The FDA need not confirm your response, but you will find it prudent to contact the agency and confirm receipt. Depending on the severity of the issue, the FDA may return for another inspection, and if the timeline has not been met or deficiencies not remediated, another 483 will be issued. In fact, 98% of Form 483 issuances are followed by another 483—this cycle could continue for months, even years.