diff --git a/CHANGELOG.md b/CHANGELOG.md
index 40c67c4be8f..49bb9d8c010 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Unreleased (develop)
 
+- changed: Lock the send confirmation slider for the rest of the scene once a broadcast has been attempted, whether the broadcast reported success or failure, and replace the generic failure card with a message that the transaction may have gone through, pointing at the block explorer or confirmation email before trying again.
+
 ## 4.51.0 (staging)
 
 - added: Push info-server attestation tokens into edge-core-js via `setAttestationToken` so the login server can skip CAPTCHA for attested devices, and allow `LOGIN_SERVER` / `INFO_SERVER` env overrides for local E2E stacks.
diff --git a/src/components/scenes/SendScene2.tsx b/src/components/scenes/SendScene2.tsx
index 050a7e8ddf2..e40739e88ae 100644
--- a/src/components/scenes/SendScene2.tsx
+++ b/src/components/scenes/SendScene2.tsx
@@ -259,6 +259,14 @@ const SendComponent: React.FC<Props> = props => {
     AddressEntryMethod | undefined
   >(undefined)
   const [hasPendingTx, setHasPendingTx] = useState<boolean>(false)
+  // Once a broadcast has been attempted, the confirm slider never re-arms on
+  // this scene, whether the broadcast reported success or failure. A failure
+  // report does not prove the transaction is absent from the network, and a
+  // re-armed slider after a real broadcast is an invitation to pay twice.
+  // The ref is what the send handler reads (it survives the FIO retry
+  // recursion); the state is what drives the render.
+  const broadcastAttemptedRef = React.useRef<boolean>(false)
+  const [broadcastAttempted, setBroadcastAttempted] = useState<boolean>(false)
   const [fioSender, setFioSender] = useState<FioSenderInfo>({
     fioAddress: fioPendingRequest?.payer_fio_address ?? '',
     fioWallet: null,
@@ -1308,10 +1316,14 @@ const SendComponent: React.FC<Props> = props => {
           'Error from before transaction route param hook: ',
           String(e)
         )
+        resetSlider()
         return
       }
 
       isSendingRef.current = true
+      // Set once broadcastTx resolves, so the catch below can tell a broadcast
+      // that reported failure apart from an error after a successful one.
+      let broadcastSucceeded = false
       try {
         // Check the OBT data fee and error if we are sending to a FIO address but NOT if we are paying
         // a FIO request since we want to make sure that can go through.
@@ -1324,12 +1336,20 @@ const SendComponent: React.FC<Props> = props => {
         }
 
         const signedTx = await coreWallet.signTx(edgeTransaction)
+
+        // From this point on the transaction may reach the network, so lock
+        // the slider for the life of this scene no matter what happens next.
+        // The render-side flag is set in the finally block, so the slider
+        // keeps its spinner while the attempt is in flight.
+        broadcastAttemptedRef.current = true
+
         let broadcastedTx: EdgeTransaction
         if (alternateBroadcast != null) {
           broadcastedTx = await alternateBroadcast(signedTx)
         } else {
           broadcastedTx = await coreWallet.broadcastTx(signedTx)
         }
+        broadcastSucceeded = true
 
         // Figure out metadata (preserve Zano alias if provided)
         let payeeName: string | undefined
@@ -1507,6 +1527,33 @@ const SendComponent: React.FC<Props> = props => {
         const errorCasted = err instanceof Error ? err : new Error(String(err))
         let error = err
 
+        if (broadcastAttemptedRef.current) {
+          // No happy path and no generic "network error": the broadcast was
+          // attempted, so tell the user exactly what we know and point them
+          // at the explorer before they consider sending again.
+          logActivity(
+            `Error ${
+              broadcastSucceeded ? 'after' : 'during'
+            } broadcastTx (txid ${edgeTransaction.txid}): ${String(err)}`
+          )
+          setError(
+            new I18nError(
+              lstrings.send_broadcast_failure_title,
+              sprintf(
+                broadcastSucceeded
+                  ? lstrings.send_broadcast_post_error_message_s
+                  : lstrings.send_broadcast_failure_message_s,
+                errorCasted.message
+              )
+            )
+          )
+          // The locked-state card is longer than a normal error, and the
+          // slider floats over the bottom of the scroll view. Scroll it into
+          // view so the whole message is readable without scrolling by hand.
+          needsScrollToEnd.current = true
+          return
+        }
+
         if (errorCasted.name === 'ErrorAlgoRecipientNotActivated') {
           error = new I18nError(
             lstrings.send_confirmation_algo_recipient_not_activated_s,
@@ -1562,7 +1609,14 @@ const SendComponent: React.FC<Props> = props => {
         setError(error)
       } finally {
         isSendingRef.current = false
-        resetSlider()
+        // The slider is idempotent once a broadcast has been attempted. Only a
+        // failure before that boundary (PIN, hooks, FIO fee check, signing)
+        // leaves the slider re-armed, because nothing could have been sent.
+        if (broadcastAttemptedRef.current) {
+          setBroadcastAttempted(true)
+        } else {
+          resetSlider()
+        }
       }
     }
   )
@@ -1880,6 +1934,11 @@ const SendComponent: React.FC<Props> = props => {
                 <EdgeAnim enter={{ type: 'fadeInDown', distance: 120 }}>
                   <SafeSlider
                     disabledText={disabledText}
+                    lockedText={
+                      broadcastAttempted
+                        ? lstrings.send_confirmation_slider_locked
+                        : undefined
+                    }
                     onSlidingComplete={handleSliderComplete}
                     disabled={disableSlider}
                   />
diff --git a/src/components/themed/SafeSlider.tsx b/src/components/themed/SafeSlider.tsx
index 6d5cc5911ce..4b228f932e7 100644
--- a/src/components/themed/SafeSlider.tsx
+++ b/src/components/themed/SafeSlider.tsx
@@ -26,6 +26,14 @@ interface Props {
   width?: number
   confirmText?: string
   disabledText?: string
+  /**
+   * When set, the slider is frozen in its completed position and shows this
+   * text instead of the spinner or the normal slide text. Use it to lock a
+   * slider after its action has run (for example, after a broadcast attempt)
+   * so it can never be slid again on this scene. Independent of `disabled`,
+   * which means "not ready yet" and shows `disabledText`.
+   */
+  lockedText?: string
   testID?: string
 
   onSlidingComplete: (reset: () => void) => Promise<void> | void
@@ -36,6 +44,7 @@ export const SafeSlider: React.FC<Props> = props => {
     confirmText,
     disabledText,
     disabled = false,
+    lockedText,
     onSlidingComplete,
     parentStyle,
     testID = 'confirmSliderThumb'
@@ -49,8 +58,11 @@ export const SafeSlider: React.FC<Props> = props => {
   const { width = theme.confirmationSliderWidth } = props
   const upperBound = width - theme.confirmationSliderThumbWidth
   const widthStyle = { width }
-  const sliderDisabled = disabled || completed
-  const sliderText = !sliderDisabled
+  const locked = lockedText != null
+  const sliderDisabled = disabled || completed || locked
+  const sliderText = locked
+    ? lockedText
+    : !sliderDisabled
     ? confirmText ?? lstrings.send_confirmation_slide_to_confirm
     : disabledText ?? lstrings.select_exchange_amount_short
 
@@ -136,7 +148,7 @@ export const SafeSlider: React.FC<Props> = props => {
             />
           </Animated.View>
         </GestureDetector>
-        {completed ? (
+        {completed && !locked ? (
           <ActivityIndicator
             color={theme.iconTappable}
             style={styles.activityIndicator}
diff --git a/src/locales/en_US.ts b/src/locales/en_US.ts
index 51f82a5058b..6288c43ec8e 100644
--- a/src/locales/en_US.ts
+++ b/src/locales/en_US.ts
@@ -528,6 +528,12 @@ const strings = {
   transaction_failure_504_message: '504 Server Timeout - Retry Transaction',
   transaction_success: 'Transaction Success',
   transaction_success_message: 'Your transaction has been successfully sent.',
+  send_broadcast_failure_title: 'Transaction Status Unknown',
+  send_broadcast_failure_message_s:
+    'The network returned an error while broadcasting this transaction, but it may still have gone through. Before trying again, check the transaction in a block explorer or wait for a confirmation email from the recipient or service. Sending again could result in a duplicate payment.\n\nError: %s',
+  send_broadcast_post_error_message_s:
+    'This transaction was broadcast to the network, but an error occurred afterwards. Check a block explorer to confirm its status. Sending again could result in a duplicate payment.\n\nError: %s',
+  send_confirmation_slider_locked: 'Send Attempted',
   incorrect_pin: 'Incorrect PIN',
   invalid_spend_request: 'Invalid Spend Request',
   invalid_custom_fee: 'Minimum custom fee is',
diff --git a/src/locales/strings/enUS.json b/src/locales/strings/enUS.json
index ecfa739a196..d761e1ac4a3 100644
--- a/src/locales/strings/enUS.json
+++ b/src/locales/strings/enUS.json
@@ -374,6 +374,10 @@
   "transaction_failure_504_message": "504 Server Timeout - Retry Transaction",
   "transaction_success": "Transaction Success",
   "transaction_success_message": "Your transaction has been successfully sent.",
+  "send_broadcast_failure_title": "Transaction Status Unknown",
+  "send_broadcast_failure_message_s": "The network returned an error while broadcasting this transaction, but it may still have gone through. Before trying again, check the transaction in a block explorer or wait for a confirmation email from the recipient or service. Sending again could result in a duplicate payment.\n\nError: %s",
+  "send_broadcast_post_error_message_s": "This transaction was broadcast to the network, but an error occurred afterwards. Check a block explorer to confirm its status. Sending again could result in a duplicate payment.\n\nError: %s",
+  "send_confirmation_slider_locked": "Send Attempted",
   "incorrect_pin": "Incorrect PIN",
   "invalid_spend_request": "Invalid Spend Request",
   "invalid_custom_fee": "Minimum custom fee is",