diff --git a/components/grid-visualizer/src/app/page.tsx b/components/grid-visualizer/src/app/page.tsx
index 14b950119..1826296b1 100644
--- a/components/grid-visualizer/src/app/page.tsx
+++ b/components/grid-visualizer/src/app/page.tsx
@@ -34,6 +34,7 @@ export default function Home() {
     setReceiveNetwork,
     setSourceFundingMode,
     setSourceRail,
+    setDestRail,
     setSettlementRail,
     swap,
     setSourceRegion,
@@ -188,8 +189,10 @@ export default function Home() {
                 <InputCard
                   label="Destination"
                   selection={state.receive}
+                  rail={state.destRail}
                   onCardClick={() => openPicker('receive')}
                   onNetworkChange={setReceiveNetwork}
+                  onRailChange={setDestRail}
                 />
               </div>
 
@@ -259,6 +262,7 @@ export default function Home() {
               sourceRegion={state.sourceRegion}
               destRegion={state.destRegion}
               sourceRail={state.sourceRail}
+              destRail={state.destRail}
               settlementRail={state.settlementRail}
               expanded={flowExpanded}
               onToggle={toggleFlow}
@@ -268,6 +272,7 @@ export default function Home() {
               receive={state.receive!}
               fundingModel={fundingModel}
               sourceRail={state.sourceRail}
+              destRail={state.destRail}
               audience={state.audience}
               onAudienceChange={setAudience}
               expanded={codeExpanded}
diff --git a/components/grid-visualizer/src/components/CodePanel/CodePanel.tsx b/components/grid-visualizer/src/components/CodePanel/CodePanel.tsx
index 02b66abdb..0686c145c 100644
--- a/components/grid-visualizer/src/components/CodePanel/CodePanel.tsx
+++ b/components/grid-visualizer/src/components/CodePanel/CodePanel.tsx
@@ -19,6 +19,7 @@ interface CodePanelProps {
   receive: CurrencySelection;
   fundingModel: 'jit' | 'pre-funded';
   sourceRail?: string | null;
+  destRail?: string | null;
   audience: 'human' | 'agent';
   onAudienceChange: (audience: 'human' | 'agent') => void;
   expanded: boolean;
@@ -271,16 +272,17 @@ export function CodePanel({
   receive,
   fundingModel,
   sourceRail,
+  destRail,
   audience,
   onAudienceChange,
   expanded,
 }: CodePanelProps) {
   const steps = useMemo(
-    () => generateSteps(send, receive, fundingModel, sourceRail),
-    [send, receive, fundingModel, sourceRail],
+    () => generateSteps(send, receive, fundingModel, sourceRail, destRail),
+    [send, receive, fundingModel, sourceRail, destRail],
   );
 
-  const stepsKey = `${send.code}-${send.accountType}-${send.isInternal}-${receive.code}-${receive.accountType}-${receive.isInternal}-${fundingModel}-${sourceRail}-${audience}`;
+  const stepsKey = `${send.code}-${send.accountType}-${send.isInternal}-${receive.code}-${receive.accountType}-${receive.isInternal}-${fundingModel}-${sourceRail}-${destRail}-${audience}`;
   const isHuman = audience === 'human';
 
   return (
diff --git a/components/grid-visualizer/src/components/CurrencyPicker/CurrencyPicker.tsx b/components/grid-visualizer/src/components/CurrencyPicker/CurrencyPicker.tsx
index fe550d0ca..3e1669fbd 100644
--- a/components/grid-visualizer/src/components/CurrencyPicker/CurrencyPicker.tsx
+++ b/components/grid-visualizer/src/components/CurrencyPicker/CurrencyPicker.tsx
@@ -5,7 +5,7 @@ import { Command } from '@lightsparkdev/origin';
 import type { CommandItem, CommandGroup } from '@lightsparkdev/origin';
 import { IconMagnifyingGlass } from '@central-icons-react/round-outlined-radius-3-stroke-1.5/IconMagnifyingGlass';
 import { useCommandNav } from '@/hooks/useCommandNav';
-import { currencies } from '@/data/currencies';
+import { currencies, railDisplayName } from '@/data/currencies';
 import { cryptoAssets } from '@/data/crypto';
 import type { CurrencySelection } from '@/lib/code-generator';
 import styles from './CurrencyPicker.module.scss';
@@ -63,7 +63,7 @@ function lookupSelection(id: string): CurrencySelection | null {
 function getRailsText(sel: CurrencySelection | null): string {
   if (!sel) return '';
   const fiat = currencies.find((c) => c.code === sel.code);
-  if (fiat) return fiat.allRails.join(', ');
+  if (fiat) return fiat.allRails.map(railDisplayName).join(', ');
   const crypto = cryptoAssets.find((a) => a.symbol === sel.code);
   if (crypto) return crypto.accountTypes.map((t) => t.network).join(', ');
   return '';
@@ -76,7 +76,7 @@ function buildFiatItem(
   return {
     id: c.code,
     label: c.name,
-    keywords: [c.code, c.accountType, ...c.allRails],
+    keywords: [c.code, c.accountType, ...c.allRails, ...c.allRails.map(railDisplayName)],
     icon: (
       // eslint-disable-next-line @next/next/no-img-element
       <img
diff --git a/components/grid-visualizer/src/components/FlowPanel/FlowPanel.tsx b/components/grid-visualizer/src/components/FlowPanel/FlowPanel.tsx
index 19a3755e2..d283be0bf 100644
--- a/components/grid-visualizer/src/components/FlowPanel/FlowPanel.tsx
+++ b/components/grid-visualizer/src/components/FlowPanel/FlowPanel.tsx
@@ -22,6 +22,7 @@ interface FlowPanelProps {
   sourceRegion?: string | null;
   destRegion?: string | null;
   sourceRail?: string | null;
+  destRail?: string | null;
   settlementRail?: string | null;
   expanded: boolean;
   onToggle: () => void;
@@ -267,11 +268,12 @@ export function FlowPanel({
   sourceRegion,
   destRegion,
   sourceRail,
+  destRail,
   settlementRail,
   expanded,
   onToggle,
 }: FlowPanelProps) {
-  const path = useMemo(() => buildFlowPath(send, receive, sourceRegion, destRegion, sourceRail, settlementRail), [send, receive, sourceRegion, destRegion, sourceRail, settlementRail]);
+  const path = useMemo(() => buildFlowPath(send, receive, sourceRegion, destRegion, sourceRail, destRail, settlementRail), [send, receive, sourceRegion, destRegion, sourceRail, destRail, settlementRail]);
   const pathKey = path.nodes.map((n) => n.id + n.label + n.isInternal + n.actionCards.map((a) => a.text).join(',')).join('|');
   const contentRef = useRef<HTMLDivElement>(null);
   const flowRef = useRef<HTMLDivElement>(null);
diff --git a/components/grid-visualizer/src/components/InputCard/InputCard.tsx b/components/grid-visualizer/src/components/InputCard/InputCard.tsx
index 4842fa8a1..37bf34cd7 100644
--- a/components/grid-visualizer/src/components/InputCard/InputCard.tsx
+++ b/components/grid-visualizer/src/components/InputCard/InputCard.tsx
@@ -4,7 +4,7 @@ import { useState, useRef, useCallback, useEffect } from 'react';
 import { createPortal } from 'react-dom';
 import type { CurrencySelection } from '@/lib/code-generator';
 import { cryptoAssets, type CryptoAccountType } from '@/data/crypto';
-import { currencies } from '@/data/currencies';
+import { currencies, railDisplayName } from '@/data/currencies';
 import { IconPlusLarge } from '@central-icons-react/round-outlined-radius-3-stroke-1.5/IconPlusLarge';
 import { IconChevronBottom } from '@central-icons-react/round-outlined-radius-3-stroke-1.5/IconChevronBottom';
 import { IconArrowsRepeat } from '@central-icons-react/round-outlined-radius-3-stroke-1.5/IconArrowsRepeat';
@@ -247,7 +247,7 @@ function RailDropdown({
       >
         <span className={styles.propertyLabel}>Rail</span>
         <span className={styles.propertyValue}>
-          <span>{selectedRail}</span>
+          <span>{railDisplayName(selectedRail)}</span>
           <span className={styles.propertyChevron}>
             <IconChevronRightSmall size={16} />
           </span>
@@ -285,7 +285,7 @@ function RailDropdown({
                     }}
                     type="button"
                   >
-                    <span>{rail}</span>
+                    <span>{railDisplayName(rail)}</span>
                   </button>
                 ))}
               </motion.div>
@@ -395,7 +395,7 @@ export function InputCard({
                 <div className={clsx(styles.propertyRow, styles.propertyRowStatic)}>
                   <span className={styles.propertyLabel}>Rail</span>
                   <span className={styles.propertyValue}>
-                    <span>{fiatRail}</span>
+                    <span>{railDisplayName(fiatRail)}</span>
                   </span>
                 </div>
               ) : null}
diff --git a/components/grid-visualizer/src/data/currencies.ts b/components/grid-visualizer/src/data/currencies.ts
index 5b7ed99d0..0b8ed0ee6 100644
--- a/components/grid-visualizer/src/data/currencies.ts
+++ b/components/grid-visualizer/src/data/currencies.ts
@@ -14,6 +14,39 @@ export interface FiatCurrency {
   examplePerson: ExamplePerson;
 }
 
+// instantRails/allRails hold PaymentRail enum members because they are sent to
+// the API as-is. These are the human-readable forms for UI text only — never
+// send a display name to the API.
+const railDisplayNames: Record<string, string> = {
+  ACH: 'ACH',
+  ACH_COLOMBIA: 'ACH Colombia',
+  BANK_TRANSFER: 'Bank Transfer',
+  BRE_B: 'Bre-B',
+  CIPS: 'CIPS',
+  FAST: 'FAST',
+  FASTER_PAYMENTS: 'Faster Payments',
+  FEDNOW: 'FedNow',
+  INSTAPAY: 'InstaPay',
+  MOBILE_MONEY: 'Mobile Money',
+  NEFT: 'NEFT',
+  PAYNOW: 'PayNow',
+  PESONET: 'PESONet',
+  PIX: 'PIX',
+  RTGS: 'RTGS',
+  RTP: 'RTP',
+  SEPA: 'SEPA',
+  SEPA_INSTANT: 'SEPA Instant',
+  SPEI: 'SPEI',
+  SWIFT: 'SWIFT',
+  UNIONPAY: 'UnionPay',
+  UPI: 'UPI',
+  WIRE: 'Wire',
+};
+
+export function railDisplayName(rail: string): string {
+  return railDisplayNames[rail] ?? rail.replace(/_/g, ' ');
+}
+
 export const currencies: FiatCurrency[] = [
   {
     code: 'USD',
@@ -21,8 +54,8 @@ export const currencies: FiatCurrency[] = [
     countryCode: 'us',
     accountType: 'USD_ACCOUNT',
     accountLabel: 'US Bank Account',
-    instantRails: ['RTP', 'FedNow'],
-    allRails: ['ACH', 'Wire', 'RTP', 'FedNow'],
+    instantRails: ['RTP', 'FEDNOW'],
+    allRails: ['ACH', 'WIRE', 'RTP', 'FEDNOW'],
     examplePerson: { fullName: 'Jane Doe', nationality: 'US' },
   },
   {
@@ -31,8 +64,8 @@ export const currencies: FiatCurrency[] = [
     countryCode: 'eu',
     accountType: 'EUR_ACCOUNT',
     accountLabel: 'IBAN',
-    instantRails: ['SEPA Instant'],
-    allRails: ['SEPA', 'SEPA Instant'],
+    instantRails: ['SEPA_INSTANT'],
+    allRails: ['SEPA', 'SEPA_INSTANT'],
     examplePerson: { fullName: 'Anna Müller', nationality: 'DE' },
   },
   {
@@ -41,8 +74,8 @@ export const currencies: FiatCurrency[] = [
     countryCode: 'gb',
     accountType: 'GBP_ACCOUNT',
     accountLabel: 'UK Bank Account',
-    instantRails: ['Faster Payments'],
-    allRails: ['Faster Payments'],
+    instantRails: ['FASTER_PAYMENTS'],
+    allRails: ['FASTER_PAYMENTS'],
     examplePerson: { fullName: 'James Wilson', nationality: 'GB' },
   },
   {
@@ -81,8 +114,8 @@ export const currencies: FiatCurrency[] = [
     countryCode: 'dk',
     accountType: 'DKK_ACCOUNT',
     accountLabel: 'IBAN',
-    instantRails: ['SEPA Instant'],
-    allRails: ['SEPA', 'SEPA Instant'],
+    instantRails: ['SEPA_INSTANT'],
+    allRails: ['SEPA', 'SEPA_INSTANT'],
     examplePerson: { fullName: 'Lars Jensen', nationality: 'DK' },
   },
   {
@@ -92,7 +125,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'NGN_ACCOUNT',
     accountLabel: 'Nigerian Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Chioma Okafor', nationality: 'NG' },
   },
   {
@@ -102,7 +135,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'CAD_ACCOUNT',
     accountLabel: 'Canadian Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Sophie Tremblay', nationality: 'CA' },
   },
   {
@@ -112,7 +145,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'PHP_ACCOUNT',
     accountLabel: 'Philippine Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Maria Santos', nationality: 'PH' },
   },
   {
@@ -121,8 +154,8 @@ export const currencies: FiatCurrency[] = [
     countryCode: 'sg',
     accountType: 'SGD_ACCOUNT',
     accountLabel: 'Singapore Bank Account',
-    instantRails: ['PayNow', 'FAST'],
-    allRails: ['PayNow', 'FAST', 'Bank Transfer'],
+    instantRails: ['PAYNOW', 'FAST'],
+    allRails: ['PAYNOW', 'FAST', 'BANK_TRANSFER'],
     examplePerson: { fullName: 'Wei Lin Tan', nationality: 'SG' },
   },
   {
@@ -132,7 +165,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'HKD_ACCOUNT',
     accountLabel: 'Hong Kong Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Emily Chan', nationality: 'HK' },
   },
   {
@@ -142,7 +175,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'IDR_ACCOUNT',
     accountLabel: 'Indonesian Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Siti Rahayu', nationality: 'ID' },
   },
   {
@@ -152,7 +185,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'KES_ACCOUNT',
     accountLabel: 'M-Pesa',
     instantRails: [],
-    allRails: ['Mobile Money'],
+    allRails: ['MOBILE_MONEY'],
     examplePerson: { fullName: 'Wanjiku Kamau', nationality: 'KE' },
   },
   {
@@ -162,7 +195,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'MYR_ACCOUNT',
     accountLabel: 'Malaysian Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Nurul Aisyah', nationality: 'MY' },
   },
   {
@@ -172,7 +205,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'RWF_ACCOUNT',
     accountLabel: 'Mobile Money',
     instantRails: [],
-    allRails: ['Mobile Money'],
+    allRails: ['MOBILE_MONEY'],
     examplePerson: { fullName: 'Jean Uwimana', nationality: 'RW' },
   },
   {
@@ -182,7 +215,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'THB_ACCOUNT',
     accountLabel: 'Thai Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Somchai Prasert', nationality: 'TH' },
   },
   {
@@ -192,7 +225,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'TZS_ACCOUNT',
     accountLabel: 'Mobile Money',
     instantRails: [],
-    allRails: ['Mobile Money'],
+    allRails: ['MOBILE_MONEY'],
     examplePerson: { fullName: 'Halima Mwanga', nationality: 'TZ' },
   },
   {
@@ -202,7 +235,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'VND_ACCOUNT',
     accountLabel: 'Vietnamese Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Nguyen Thi Lan', nationality: 'VN' },
   },
   {
@@ -212,7 +245,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'ZAR_ACCOUNT',
     accountLabel: 'South African Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer'],
+    allRails: ['BANK_TRANSFER'],
     examplePerson: { fullName: 'Thabo Nkosi', nationality: 'ZA' },
   },
   {
@@ -222,7 +255,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'ZMW_ACCOUNT',
     accountLabel: 'Mobile Money',
     instantRails: [],
-    allRails: ['Mobile Money'],
+    allRails: ['MOBILE_MONEY'],
     examplePerson: { fullName: 'Mwila Tembo', nationality: 'ZM' },
   },
   {
@@ -232,7 +265,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'MWK_ACCOUNT',
     accountLabel: 'Mobile Money',
     instantRails: [],
-    allRails: ['Mobile Money'],
+    allRails: ['MOBILE_MONEY'],
     examplePerson: { fullName: 'Chimwemwe Banda', nationality: 'MW' },
   },
   {
@@ -242,7 +275,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'UGX_ACCOUNT',
     accountLabel: 'Mobile Money',
     instantRails: [],
-    allRails: ['Mobile Money'],
+    allRails: ['MOBILE_MONEY'],
     examplePerson: { fullName: 'Grace Namugga', nationality: 'UG' },
   },
   {
@@ -252,7 +285,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'XOF_ACCOUNT',
     accountLabel: 'Mobile Money',
     instantRails: [],
-    allRails: ['Mobile Money'],
+    allRails: ['MOBILE_MONEY'],
     examplePerson: { fullName: 'Amadou Diallo', nationality: 'SN' },
   },
   {
@@ -262,7 +295,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'SLV_ACCOUNT',
     accountLabel: 'El Salvador Bank/Mobile',
     instantRails: [],
-    allRails: ['Bank Transfer', 'Mobile Money'],
+    allRails: ['BANK_TRANSFER', 'MOBILE_MONEY'],
     examplePerson: { fullName: 'Carlos Morales', nationality: 'SV' },
   },
   {
@@ -272,7 +305,7 @@ export const currencies: FiatCurrency[] = [
     accountType: 'CNY_ACCOUNT',
     accountLabel: 'Chinese Bank Account',
     instantRails: [],
-    allRails: ['Bank Transfer', 'Mobile Money'],
+    allRails: ['BANK_TRANSFER', 'MOBILE_MONEY'],
     examplePerson: { fullName: 'Wei Zhang', nationality: 'CN' },
   },
 ];
diff --git a/components/grid-visualizer/src/hooks/useFlowBuilder.ts b/components/grid-visualizer/src/hooks/useFlowBuilder.ts
index b4e63dcba..7781388a1 100644
--- a/components/grid-visualizer/src/hooks/useFlowBuilder.ts
+++ b/components/grid-visualizer/src/hooks/useFlowBuilder.ts
@@ -15,6 +15,7 @@ export interface FlowBuilderState {
   destRegion: string | null;   // fiat code — only used when destination is crypto
   sourceFundingMode: SourceFundingMode;
   sourceRail: string | null;   // selected fiat rail e.g. 'RTP' — null for crypto
+  destRail: string | null;     // selected fiat rail — sent as the quote's destination.paymentRail
   settlementRail: string;      // asset Grid settles over between switches, e.g. 'BTC' | 'USDC' | 'USDB'
   audience: 'human' | 'agent';
   pickerTarget: 'send' | 'receive' | null;
@@ -27,6 +28,7 @@ type Action =
   | { type: 'SET_RECEIVE_NETWORK'; payload: CryptoAccountType }
   | { type: 'SET_SOURCE_FUNDING_MODE'; payload: SourceFundingMode }
   | { type: 'SET_SOURCE_RAIL'; payload: string }
+  | { type: 'SET_DEST_RAIL'; payload: string }
   | { type: 'SET_SETTLEMENT_RAIL'; payload: string }
   | { type: 'SET_SOURCE_REGION'; payload: string }
   | { type: 'SET_DEST_REGION'; payload: string }
@@ -43,6 +45,7 @@ const initialState: FlowBuilderState = {
   destRegion: null,
   sourceFundingMode: 'external',
   sourceRail: null,
+  destRail: null,
   settlementRail: DEFAULT_SETTLEMENT_RAIL,
   audience: 'human',
   pickerTarget: null,
@@ -70,7 +73,8 @@ function reducer(state: FlowBuilderState, action: Action): FlowBuilderState {
       const destRegion = receive.type === 'crypto'
         ? (receive.code === 'BTC' ? (state.destRegion ?? null) : 'USD')
         : null;
-      return { ...state, receive, destRegion, pickerTarget: null };
+      const destRail = receive.type === 'fiat' ? getDefaultRail(receive.code) : null;
+      return { ...state, receive, destRegion, destRail, pickerTarget: null };
     }
     case 'SET_SEND_NETWORK': {
       if (!state.send) return state;
@@ -119,6 +123,8 @@ function reducer(state: FlowBuilderState, action: Action): FlowBuilderState {
     }
     case 'SET_SOURCE_RAIL':
       return { ...state, sourceRail: action.payload };
+    case 'SET_DEST_RAIL':
+      return { ...state, destRail: action.payload };
     case 'SET_SETTLEMENT_RAIL':
       return { ...state, settlementRail: action.payload };
     case 'SET_SOURCE_REGION':
@@ -133,16 +139,18 @@ function reducer(state: FlowBuilderState, action: Action): FlowBuilderState {
       return { ...state, pickerTarget: null };
     case 'SWAP': {
       const newSend = state.receive;
+      const newReceive = state.send;
       const sourceFundingMode: SourceFundingMode = newSend?.type === 'crypto'
         ? 'realtime'
         : 'external';
       return {
         ...state,
         send: newSend,
-        receive: state.send,
+        receive: newReceive,
         sourceRegion: state.destRegion,
         destRegion: state.sourceRegion,
         sourceRail: newSend?.type === 'fiat' ? getDefaultRail(newSend.code) : null,
+        destRail: newReceive?.type === 'fiat' ? getDefaultRail(newReceive.code) : null,
         sourceFundingMode,
       };
     }
@@ -228,6 +236,11 @@ export function useFlowBuilder() {
     [],
   );
 
+  const setDestRail = useCallback(
+    (rail: string) => dispatch({ type: 'SET_DEST_RAIL', payload: rail }),
+    [],
+  );
+
   const setSettlementRail = useCallback(
     (asset: string) => dispatch({ type: 'SET_SETTLEMENT_RAIL', payload: asset }),
     [],
@@ -271,6 +284,7 @@ export function useFlowBuilder() {
     setReceiveNetwork,
     setSourceFundingMode,
     setSourceRail,
+    setDestRail,
     setSettlementRail,
     setSourceRegion,
     setDestRegion,
diff --git a/components/grid-visualizer/src/lib/code-generator.ts b/components/grid-visualizer/src/lib/code-generator.ts
index c93930cdf..4c7c34161 100644
--- a/components/grid-visualizer/src/lib/code-generator.ts
+++ b/components/grid-visualizer/src/lib/code-generator.ts
@@ -1,5 +1,5 @@
 import { accountTypeSpecs } from '@/data/account-types';
-import { currencies } from '@/data/currencies';
+import { currencies, railDisplayName } from '@/data/currencies';
 
 export interface ExamplePerson {
   fullName: string;
@@ -67,11 +67,11 @@ function getJitPaymentMethod(source: CurrencySelection, sourceRail: string | nul
     return 'crypto transfer';
   }
   if (sourceRail) {
-    return `${sourceRail} transfer`;
+    return `${railDisplayName(sourceRail)} transfer`;
   }
   const fiat = currencies.find((c) => c.code === source.code);
   if (fiat && fiat.instantRails.length > 0) {
-    return `${fiat.instantRails[0]} transfer`;
+    return `${railDisplayName(fiat.instantRails[0])} transfer`;
   }
   return 'bank transfer';
 }
@@ -88,6 +88,7 @@ export function generateSteps(
   destination: CurrencySelection,
   fundingModel: 'jit' | 'pre-funded',
   sourceRail?: string | null,
+  destRail?: string | null,
 ): ApiStep[] {
   const jitFunding = fundingModel === 'jit';
   const steps: ApiStep[] = [];
@@ -267,6 +268,14 @@ export function generateSteps(
         destinationType: 'ACCOUNT',
         accountId: 'ExternalAccount:<external_account_id>',
       };
+      // Singular `paymentRail` is a request field on the quote destination and
+      // is optional — omitted, Grid picks a default. The plural `paymentRails`
+      // is response-only (it reports what an account supports) and must never
+      // be sent. Internal destinations are excluded: funds credited to a Grid
+      // balance never traverse an external rail.
+      if (destination.type === 'fiat' && destRail) {
+        quoteDest.paymentRail = destRail;
+      }
     } else {
       quoteDest = {
         destinationType: 'ACCOUNT',
diff --git a/components/grid-visualizer/src/lib/flow-path.ts b/components/grid-visualizer/src/lib/flow-path.ts
index 09222ef5e..e6b3b3775 100644
--- a/components/grid-visualizer/src/lib/flow-path.ts
+++ b/components/grid-visualizer/src/lib/flow-path.ts
@@ -1,5 +1,5 @@
 import type { CurrencySelection } from './code-generator';
-import { currencies } from '@/data/currencies';
+import { currencies, railDisplayName } from '@/data/currencies';
 import { getSettlementRail } from '@/data/settlement-rails';
 
 export type ActionColor = 'fiat' | 'btc' | 'stable';
@@ -89,6 +89,7 @@ export function buildFlowPath(
   sourceRegion?: string | null,
   destRegion?: string | null,
   sourceRail?: string | null,
+  destRail?: string | null,
   settlementRail?: string | null,
 ): FlowPath {
   const nodes: FlowNode[] = [];
@@ -266,15 +267,18 @@ export function buildFlowPath(
 
     if (curr.type === 'endpoint' && !curr.isInternal && next.type === 'switch') {
       const srcFiatData = source.type === 'fiat' ? currencies.find((c) => c.code === source.code) : null;
-      const srcRail = sourceRail
-        ?? (srcFiatData
-          ? (srcFiatData.instantRails[0] ?? srcFiatData.allRails[0] ?? source.accountLabel)
-          : (source.network ?? source.accountLabel));
+      const srcRailValue = sourceRail
+        ?? (srcFiatData ? (srcFiatData.instantRails[0] ?? srcFiatData.allRails[0]) : null);
+      const srcRail = srcRailValue
+        ? railDisplayName(srcRailValue)
+        : (source.network ?? source.accountLabel);
       text = `Funds in via ${srcRail}`;
     } else if (curr.type === 'switch' && next.type === 'endpoint' && !next.isInternal) {
       const dstFiatData = destination.type === 'fiat' ? currencies.find((c) => c.code === destination.code) : null;
-      const dstRail = dstFiatData
-        ? (dstFiatData.instantRails[0] ?? dstFiatData.allRails[0] ?? destination.accountLabel)
+      const dstRailValue = destRail
+        ?? (dstFiatData ? (dstFiatData.instantRails[0] ?? dstFiatData.allRails[0]) : null);
+      const dstRail = dstRailValue
+        ? railDisplayName(dstRailValue)
         : (destination.network ?? destination.accountLabel);
       text = `Funds out via ${dstRail}`;
     } else if (curr.type === 'switch' && next.type === 'switch') {