I need urgent clarification regarding the new reimbursement policy and the process for submitting sourcing cost information.

As a large-volume seller with thousands of ASINs in active inventory, I’ve noticed that under the new reimbursement approach, Amazon appears to default to a "manufacturing cost" value that is significantly lower than our actual sourcing costs in almost all cases. This discrepancy could result in substantial under-reimbursement for lost or damaged inventory.

However, proactively submitting detailed cost documentation for thousands of ASINs—many of which may never require reimbursement—is not practically feasible without dedicating a full-time employee solely to this task. This is clearly an inefficient and unnecessary use of resources for us and for Amazon.

Given that most reimbursements are automatically issued and that cost data is only relevant if a reimbursement occurs and the default value is incorrect, I would like to clarify the following:

Can we upload correct cost documentation after a reimbursement has been issued and we disagree with the reimbursed amount—rather than preemptively for every ASIN?

This would be a far more scalable and logical approach for sellers managing large catalogs. I hope Amazon can confirm whether this is permitted and, if so, provide guidance on the process and timeline for disputing a reimbursement amount with supporting cost documentation.

This issue has significant operational and financial implications, and I’d greatly appreciate a prompt and clear response.