Polygon 128-Confirmation Requirement

The 128-block confirmation threshold exists to protect against chain reorganizations (reorgs). A reorg occurs when validators discard recently added blocks and replace them with a different chain. Until 128 blocks have passed, an early block in the chain could theoretically be reversed. By waiting 128 confirmations, exchanges ensure the transaction is deeply embedded and irreversible.

With Polygon's ~2-second block time, 128 confirmations take approximately 256 seconds, or about 4 to 5 minutes. This is a fixed number, but actual clock time can vary slightly based on real-time block production speed and network load.

Many major exchanges including IDEX, and platforms following standard Polygon deposit policies, require 128 blocks before finality is recognized. Some platforms like Circle (for USDC on Polygon PoS) require as few as 50 confirmations (~2 minutes). Always check the specific exchange's requirements.

If your Polygon deposit shows as pending after 10 minutes, it is likely due to a low gas fee causing the transaction itself to be delayed, not the confirmation count. Check the transaction hash on PolygonScan to see how many confirmations have passed and whether the transaction has been included in a block.