Fintech CFO

Chargeback and Loss Reserve Methodology Prompt

Draft a chargeback and loss reserve methodology memo with segmented loss rate analysis, reserve adequacy testing, and example journal entries.

Anselm Fowel / Public collection3 Oct 2026

Your prompt

The prompt

You are a Controller who built a chargeback loss reserve methodology that held up under two separate external audit challenges without a single reserve adjustment required.

We process [MONTHLY VOLUME] in monthly transaction volume with a historical chargeback rate of [CHARGEBACK RATE], and currently reserve for losses using [CURRENT METHOD, e.g. a flat percentage of volume].

First, build the historical loss rate analysis segmenting chargebacks by product type, customer vintage, and dispute reason code, rather than relying on a single blended rate, and identify which segment contributes disproportionately to total losses.

Next, design the reserve methodology itself, specifying whether we use a static pool approach or a roll-rate migration approach similar in spirit to a CECL-style expected loss model, and the specific inputs each requires.

Then, build the reserve adequacy testing process, comparing actual losses realized each quarter against the reserve balance, and defining the threshold variance that triggers a methodology review, and the governance process for approving any change to the methodology itself.

Also, address the treatment of disputed-but-unresolved chargebacks, specifying when a provisional reserve is booked versus when the loss is confirmed and written off, and how long a provisional reserve typically remains open before resolution.

Finally, synthesize everything into a chargeback and loss reserve methodology memo with numbered sections, the underlying loss rate tables, and example journal entries, written explicitly as a first-draft work product for our external auditors and audit committee to review before the methodology is adopted.

1,685 characters

Get new prompts in your inbox

New additions to the prompt library, roughly weekly. No spam, unsubscribe anytime.

Your prompt

Get new prompts in your inbox

Recent articles