What does HRESULT 0x8004000C (TAPI_E_INVALADDRESS) mean?

TAPI_E_INVALADDRESS

TAPI_E_INVALADDRESS: diagnose the owning boundary

TAPI_E_INVALADDRESS (0x8004000C) is documented as The phone number is invalid or not properly formatted. Treat that wording as the specific TAPI address selection boundary; it is more useful than a generic “component failed” label.

Evidence that matters

Record line device, address ID/string, media mode, call privilege and the exact TAPI call. Enumerate addresses on that same line and retry with a valid address.

Interpretation and verification

Keep the affected object and caller identity stable while changing only the rejected prerequisite. The correction is proven when the original operation crosses this boundary with the intended state or output. If a different HRESULT appears afterward, preserve it as a separate later-stage result rather than folding it back into TAPI_E_INVALADDRESS.

Technical references

• TAPI overview.
• LINECALLPARAMS.