The FCC’s grace period for its new uniform call‑blocking notification rule is coming to an end. As of March 25, 2026, full compliance with the Federal Communications Commission’s Eighth Report and Order on call‑blocking transparency and redress will be required. For businesses that rely on outbound calling, now is the time to confirm that your providers, and your contracts, are ready.
Under the FCC’s order, SIP Code 603+ is now the mandatory and exclusive method for notifying callers when voice calls are blocked based on “reasonable analytics.” For the past year, providers were permitted to transition away from older SIP codes (603, 607, and 608). That transition period is ending.
Unlike the standard SIP 603 code, which typically displays as “Decline,” 603+ displays as “Network Blocked.” It also includes standardized information indicating that the call was blocked based on analytics, along with contact details for the blocking provider. These changes are designed to meet the TRACED Act’s transparency and redress requirements, ensuring that legitimate callers know when their calls are blocked, why the block occurred, and how to seek resolution.
The order also expands Do‑Not‑Originate (DNO) blocking, requiring all voice service providers in the call path to block calls from numbers on a reasonable DNO list. While DNO blocking is separate from SIP 603+ notifications, it reflects the FCC’s continued efforts to stop illegal calls earlier in the network.
Notably, the SIP 603+ applies only to voice calls blocked due to reasonable analytics. It does not apply to text messages, call labeling (such as “Spam Likely”), or calls blocked for other reasons.
With the compliance deadline just weeks away, businesses should:
- confirm that their voice service providers are fully implementing SIP Code 603+;
- understand how blocking notifications and redress requests will be handled; and
- review contracts to ensure providers are obligated to support FCC‑mandated transparency and redress.
The FCC has made clear that call‑blocking transparency is no longer optional. If your calls are being blocked, you should know it—and have a clear path to fix it.
