# Network timelines (https://docs.chargeflow.io/docs/reference/concepts/network-timelines)
Every card network sets its own clock for disputes. Miss a response window and the case is lost by default, even when the evidence is strong. This page summarizes the typical windows for Visa, Mastercard, American Express, and Discover so you know how much time each stage allows.
## Response windows by network [#response-windows-by-network]
The windows below are the common defaults. They are counted in calendar days from the dispute date unless noted.
| Stage | Visa | Mastercard | American Express | Discover |
| --------------------------------- | ------------------------------------------------------------------------------------- | -------------- | ---------------- | -------------- |
| Cardholder filing window | Up to 120 days from the transaction or expected delivery (up to 540 for some reasons) | Up to 120 days | Up to 120 days | Up to 120 days |
| Merchant response (representment) | 30 days | 45 days | 20 days | 30 days |
| Issuer review | Several weeks | Several weeks | Several weeks | Several weeks |
| Pre-arbitration response | 30 days | 45 days | 20 days | 30 days |
| Arbitration filing | 10 days after pre-arbitration | 45 days | Varies | Varies |
These are typical defaults. The exact window depends on the specific reason code, the region, and
the cardholder's situation. Some Visa reasons, for example, extend the filing window well beyond
120 days. Always confirm the deadline shown on the individual dispute with your PSP or the network
before you rely on it.
## Why the clock matters [#why-the-clock-matters]
The merchant response window is the deadline that matters most for recovery. If you do not submit a rebuttal in time, the dispute resolves in the cardholder's favor automatically. Networks count the window from the dispute date, not the date you were notified, so any delay between the issuer posting the chargeback and your PSP surfacing it eats into your available time.
Chargeflow ingests disputes as soon as they post and submits the rebuttal well inside the window, which removes the risk of a missed deadline. See [Dispute automation engine](https://docs.chargeflow.io/docs/reference/concepts/dispute-automation).
## Inquiries and retrieval requests [#inquiries-and-retrieval-requests]
Before a full chargeback, some networks issue an inquiry or retrieval request asking for transaction documents. These often carry shorter windows, frequently in the range of 24 to 72 hours for the initial document request and a few weeks for a full response. Responding to an inquiry promptly can prevent it from escalating into a chargeback. See [Dispute state machine](https://docs.chargeflow.io/docs/reference/concepts/dispute-state-machine).
## Next steps [#next-steps]
How a dispute moves through each timed stage.
The stages and statuses tied to these windows.
What to submit before the response window closes.
How the reason affects the applicable window.