diff --git a/agents/telephony/byo-sip.mdx b/agents/telephony/byo-sip.mdx
index 5b36249..2d8c3f6 100644
--- a/agents/telephony/byo-sip.mdx
+++ b/agents/telephony/byo-sip.mdx
@@ -122,7 +122,9 @@ Set both when your carrier supports it.
   </Step>
   <Step title="Allow transfers (optional)">
     For [cold transfers](/agents/telephony/transfers), enable **Call Transfer
-    (SIP REFER)** in the trunk's settings so Twilio honors the handoff.
+    (SIP REFER)** in the trunk's settings and also allow transfers to the PSTN.
+    If transfers are limited to SIP destinations, Twilio rejects every transfer
+    to a phone number, so transfers to phone numbers won't work.
   </Step>
 </Steps>
 
diff --git a/agents/telephony/transfers.mdx b/agents/telephony/transfers.mdx
index 00bf2bd..2da432e 100644
--- a/agents/telephony/transfers.mdx
+++ b/agents/telephony/transfers.mdx
@@ -17,7 +17,7 @@ Two modes decide what the handoff feels like:
 ## Prerequisites
 
 - A phone number bound to your agent, answering inbound calls. See [Inbound calls](/agents/telephony/inbound-calls).
-- The number must support transfers. Numbers purchased from the platform inventory (`provider: "twilio"`) do; see [Phone numbers](/agents/telephony/phone-numbers). [Imported SIP numbers](/agents/telephony/byo-sip) support cold transfers when the carrier honors SIP REFER, and warm transfers when a termination is configured.
+- The number must support transfers. Numbers purchased from the platform inventory (`provider: "twilio"`) do; see [Phone numbers](/agents/telephony/phone-numbers). [Imported SIP numbers](/agents/telephony/byo-sip) support cold transfers when the carrier honors SIP REFER to the destination (on Twilio, enable Call Transfer and allow PSTN transfers on the trunk), and warm transfers when a termination is configured.
 
 ## Configure destinations
 
@@ -185,7 +185,6 @@ curl --request PATCH "https://api.fish.audio/v1/agent/agents/$AGENT_ID/config" \
 ## Limitations
 
 - **Phone calls only**: web and SDK sessions have no phone leg to hand off, so the `transfer_call` tool never ships for them.
-- **Transfer-capable numbers**: the number the caller dialed must be a `twilio`-provider number.
 - **Supported countries**: destination numbers are limited to an allowlist of country codes.
 
 ## Billing