SIP Error Codes Explained
What SIP error codes like 403, 404, 480, 486, 487, 503, and 603 mean for your BubblyPhone calls. Plain-language explanations and how to fix each one.
When you expand the Technical Details section on a call detail page, you may see a SIP error code. These are standard telecom codes used across the phone industry. Here is what each code means:
| Code | Meaning | What It Means For You |
|---|---|---|
| 403 | Forbidden | The carrier blocked this call. This can happen with international routing restrictions. Some countries or carriers restrict incoming calls from certain regions. |
| 404 | Not Found | The phone number does not exist or is no longer in service. Double-check the number and country code. |
| 408 | Request Timeout | The call could not be connected in time. The recipient's phone may be turned off or out of range. |
| 480 | Temporarily Unavailable | The recipient is temporarily unavailable. Their phone may be turned off, in airplane mode, or outside of coverage area. Try again later. |
| 486 | Busy Here | The recipient is currently on another call. Try calling back in a few minutes. |
| 487 | Request Terminated | The call was ended before it was answered. This usually means you cancelled the call before the other person picked up. You are not charged for this. |
| 500 | Server Internal Error | A temporary issue with the phone network. This is not something on your end. Try again in a minute — it usually resolves on its own. |
| 503 | Service Unavailable | The phone network is temporarily overloaded or undergoing maintenance. Try again later. |
| 603 | Decline | The recipient actively rejected the call. They saw the incoming call and chose not to answer. |
| 607 | Unwanted | The call was marked as unwanted by the recipient's carrier or spam filter. This can happen when the recipient's carrier has aggressive call screening enabled. |
| 608 | Rejected | Similar to 607 — the call was filtered out by anti-spam measures on the recipient's carrier or device. |
These codes are industry-standard and not specific to BubblyPhone. For a plain-language explanation of why calls fail, see Why Did My Call Fail? If you see a code not listed here, or need help understanding what happened with a specific call, contact our support team at hello@bubblyphone.com.