The OPC Foundation develops and maintains the OPC UA specifications, publishes them openly, runs accredited certification test labs and compliance test tools, and maintains the UA-.NETStandard reference implementation on GitHub.
OT Fabric is not affiliated with OPC Foundation. This profile is independent and based on the organization's own published pages, linked next to each fact. OPC Foundation is the authority on its terms and fees.
Each question is separate, because "open" and "free" mean different things here. A yes always means open or free to someone who is not a member.
Published examples as listed on the organization's pages on 23 Oct 2026. Where a page does not say whether a fee recurs, we do not guess.
| Tier | Published fee | Who can join | Votes | Working groups | Source |
|---|---|---|---|---|---|
| UA Logo | Free | Companies that offer OPC UA products.Certification lab access at the logo-member rate; test tools as a service. | No | No | opcfoundation.org |
| Startup | $500 a year | First five years and revenue under $2M.Compliance test tools and certification lab access included. | Yes | Yes | opcfoundation.org |
| Non-Voting | $900 a year | Government, research, universities and non-profits that do not build or market OPC products. | No | Yes | opcfoundation.org |
| End-User | $1,800 a year | Organizations that use OPC-based products. | Yes | Yes | opcfoundation.org |
| Corporate, classes D to A | $3,000 to $18,000 a year | By annual sales: Class D under $2M ($3,000), C $2M to $20M ($4,800), B $20M to $100M ($9,600), A $100M to $1B ($18,000).Free compliance test tools; 50% discount at the certification lab. | Yes | Yes | opcfoundation.org |
| Corporate, classes AA and AAA | Unknown | Sales over $1B.The dues table shows two 2027 figures per class without saying which applies, so we do not repeat them here. | Yes | Yes | opcfoundation.org |
OPC Foundation MIT · on the ecosystem mapOPC UA is one of the few industrial standards where a non-member can read the current specifications without paying, and where the standards body itself maintains an open-source reference stack. That combination makes independent implementations practical.
The membership ladder is unusually fine-grained. A company with an OPC UA product can join as a UA Logo member for $0 and certify, a young company can vote and join working groups as a Startup for $500, and research bodies and non-profits get working-group access as Non-Voting members for $900.
Certification is not open to non-members, but the lowest route to it is the free logo membership. The day rate at the test lab is twice as high for logo members as for Corporate members, so the cheapest route on paper is not always the cheapest in practice.
Independent open-source work on the same protocols. Listing them here does not mean they are certified by or associated with OPC Foundation.
OPC UA client and server over TCP, WebSockets and HTTPS, in UA Binary and UA JSON: RSA and ECC security, subscriptions, alarms and conditions, data and event history, GDS certificate management and PubSub.
go get github.com/otfabric/go-opcuaDiscover, browse, read, write, call methods, monitor, handle alarms, manage certificates, read and edit history, work with OPC UA PubSub, and run a test server.
OPC UA reference clients and servers: open62541, Eclipse Milo, async-opcua, UA-.NETStandard (with its GDS), node-opcua and opcua-asyncio.
Verified on 23 Oct 2026; due for a re-check by 21 Apr 2027 (180 days). Found something out of date? Report a correction or edit the data on GitHub.