The short answer
OptBlue is American Express's wholesale program that lets regular US acquirers (Chase Payment Solutions, Elavon, Worldpay, Heartland, First Data/Fiserv, etc.) underwrite and price Amex acceptance as part of a single merchant account, alongside Visa and Mastercard. Before OptBlue, Amex acceptance required a separate direct relationship with Amex (called an "ESA" or "Employer Identification Number account"), which meant a second application, second set of rates, and second settlement stream. OptBlue folded it all into one.
How it works
- When you sign up for a merchant account with most US acquirers, Amex is automatically included via OptBlue unless you opt out or cross the volume threshold.
- The acquirer charges you a single blended rate (or interchange-plus markup) that covers Visa, Mastercard, Discover, and Amex.
- Your statement shows Amex transactions like any other network; Amex settlement comes through the same payout.
- You sign one merchant agreement, not two.
Pricing under OptBlue
Amex interchange under OptBlue is published publicly and runs roughly:
- Low ticket (under $25): 1.60% + $0.05 to 2.40% + $0.05.
- Standard CNP rewards: 2.65% + $0.10.
- Premium CNP rewards: 2.95-3.25% + $0.10.
- Corporate: 3.30%+ on CNP.
Your acquirer adds the same markup on Amex that they do on Visa/Mastercard (25-50 bps typically on IC+ at mid-market volume). That makes Amex under OptBlue about 20-40 bps more expensive than a premium-rewards Visa/Mastercard transaction in the same portfolio.
The volume threshold
OptBlue has a hard cap: roughly $1M/year in Amex volume per merchant. If your Amex volume exceeds the cap, Amex requires you to move to a direct ESA contract negotiated directly with Amex. The exact cap floats; as of 2026 most acquirers flag merchants approaching $800k/year in Amex volume for transition.
OptBlue vs direct Amex (ESA)
- OptBlue: Included in your regular acquirer contract. One statement, one settlement. Capped at ~$1M/yr Amex volume.
- Direct ESA: Separate contract with Amex. Separate statement, separate settlement. No volume cap. Pricing negotiated directly with Amex, often sharper on high-volume accounts.
What operators need to know
- You probably have OptBlue and don't know it. If your acquirer accepts Amex and you don't remember signing a separate Amex contract, you're on OptBlue.
- Amex is more expensive than Visa/Mastercard on CNP. Premium rewards Amex on CNP can hit 3.4-3.6% effective rate including your acquirer's markup. Know this before quoting customers flat pricing.
- You can decline Amex acceptance. Some acquirers let you opt out of OptBlue and only accept Visa/Mastercard/Discover. Useful if your Amex volume is small and the extra 30-40 bps of interchange isn't worth the added fees.
- Transition to ESA is usually worth it at $1M+/yr Amex. Direct Amex will quote 10-30 bps cheaper at that tier. Your acquirer may resist the transition — push for it.
- Multi-brand operators usually want OptBlue across all brands. Simplicity beats the minor pricing benefit of per-brand direct Amex at most portfolio sizes under $10M/yr combined Amex volume.
See also interchange, card brand assessment, and network assessments.