diff --git a/packages/desktop-client/src/accounts/accountsSlice.ts b/packages/desktop-client/src/accounts/accountsSlice.ts
index d58feb9207..6620881cfd 100644
--- a/packages/desktop-client/src/accounts/accountsSlice.ts
+++ b/packages/desktop-client/src/accounts/accountsSlice.ts
@@ -245,17 +245,30 @@ export const unlinkAccount = createAppAsyncThunk(
   },
 );
 
-type LinkAccountPayload = {
+// Shared base type for link account payloads
+type LinkAccountBasePayload = {
+  upgradingId?: AccountEntity['id'];
+  offBudget?: boolean;
+  startingDate?: string;
+  startingBalance?: number;
+};
+
+type LinkAccountPayload = LinkAccountBasePayload & {
   requisitionId: string;
   account: SyncServerGoCardlessAccount;
-  upgradingId?: AccountEntity['id'] | undefined;
-  offBudget?: boolean | undefined;
 };
 
 export const linkAccount = createAppAsyncThunk(
   `${sliceName}/linkAccount`,
   async (
-    { requisitionId, account, upgradingId, offBudget }: LinkAccountPayload,
+    {
+      requisitionId,
+      account,
+      upgradingId,
+      offBudget,
+      startingDate,
+      startingBalance,
+    }: LinkAccountPayload,
     { dispatch },
   ) => {
     await send('gocardless-accounts-link', {
@@ -263,50 +276,64 @@ export const linkAccount = createAppAsyncThunk(
       account,
       upgradingId,
       offBudget,
+      startingDate,
+      startingBalance,
     });
     dispatch(markPayeesDirty());
     dispatch(markAccountsDirty());
   },
 );
 
-type LinkAccountSimpleFinPayload = {
+type LinkAccountSimpleFinPayload = LinkAccountBasePayload & {
   externalAccount: SyncServerSimpleFinAccount;
-  upgradingId?: AccountEntity['id'] | undefined;
-  offBudget?: boolean | undefined;
 };
 
 export const linkAccountSimpleFin = createAppAsyncThunk(
   `${sliceName}/linkAccountSimpleFin`,
   async (
-    { externalAccount, upgradingId, offBudget }: LinkAccountSimpleFinPayload,
+    {
+      externalAccount,
+      upgradingId,
+      offBudget,
+      startingDate,
+      startingBalance,
+    }: LinkAccountSimpleFinPayload,
     { dispatch },
   ) => {
     await send('simplefin-accounts-link', {
       externalAccount,
       upgradingId,
       offBudget,
+      startingDate,
+      startingBalance,
     });
     dispatch(markPayeesDirty());
     dispatch(markAccountsDirty());
   },
 );
 
-type LinkAccountPluggyAiPayload = {
+type LinkAccountPluggyAiPayload = LinkAccountBasePayload & {
   externalAccount: SyncServerPluggyAiAccount;
-  upgradingId?: AccountEntity['id'];
-  offBudget?: boolean;
 };
 
 export const linkAccountPluggyAi = createAppAsyncThunk(
   `${sliceName}/linkAccountPluggyAi`,
   async (
-    { externalAccount, upgradingId, offBudget }: LinkAccountPluggyAiPayload,
+    {
+      externalAccount,
+      upgradingId,
+      offBudget,
+      startingDate,
+      startingBalance,
+    }: LinkAccountPluggyAiPayload,
     { dispatch },
   ) => {
     await send('pluggyai-accounts-link', {
       externalAccount,
       upgradingId,
       offBudget,
+      startingDate,
+      startingBalance,
     });
     dispatch(markPayeesDirty());
     dispatch(markAccountsDirty());
diff --git a/packages/desktop-client/src/components/modals/SelectLinkedAccountsModal.tsx b/packages/desktop-client/src/components/modals/SelectLinkedAccountsModal.tsx
index 91e7aecedb..1e0f88bad2 100644
--- a/packages/desktop-client/src/components/modals/SelectLinkedAccountsModal.tsx
+++ b/packages/desktop-client/src/components/modals/SelectLinkedAccountsModal.tsx
@@ -1,15 +1,18 @@
-import React, { useMemo, useState } from 'react';
+import { useEffect, useMemo, useState } from 'react';
 import { Trans, useTranslation } from 'react-i18next';
 
 import { Button } from '@actual-app/components/button';
 import { useResponsive } from '@actual-app/components/hooks/useResponsive';
+import { Input } from '@actual-app/components/input';
 import { SpaceBetween } from '@actual-app/components/space-between';
 import { styles } from '@actual-app/components/styles';
 import { Text } from '@actual-app/components/text';
 import { theme } from '@actual-app/components/theme';
 import { Tooltip } from '@actual-app/components/tooltip';
 import { View } from '@actual-app/components/view';
+import { format as formatDate, parseISO } from 'date-fns';
 
+import { currentDay, subDays } from 'loot-core/shared/months';
 import {
   type AccountEntity,
   type SyncServerGoCardlessAccount,
@@ -41,9 +44,13 @@ import {
   Table,
   TableHeader,
 } from '@desktop-client/components/table';
+import { AmountInput } from '@desktop-client/components/util/AmountInput';
 import { useAccounts } from '@desktop-client/hooks/useAccounts';
+import { useDateFormat } from '@desktop-client/hooks/useDateFormat';
 import { useFormat } from '@desktop-client/hooks/useFormat';
 import { closeModal } from '@desktop-client/modals/modalsSlice';
+import { transactions } from '@desktop-client/queries';
+import { liveQuery } from '@desktop-client/queries/liveQuery';
 import { useDispatch } from '@desktop-client/redux';
 
 function useAddBudgetAccountOptions() {
@@ -61,6 +68,20 @@ function useAddBudgetAccountOptions() {
   return { addOnBudgetAccountOption, addOffBudgetAccountOption };
 }
 
+/**
+ * Helper to determine if the chosen account option represents creating a new account.
+ */
+function isNewAccountOption(
+  chosenAccountId: string | undefined,
+  addOnBudgetOptionId: string,
+  addOffBudgetOptionId: string,
+): boolean {
+  return (
+    chosenAccountId === addOnBudgetOptionId ||
+    chosenAccountId === addOffBudgetOptionId
+  );
+}
+
 export type SelectLinkedAccountsModalProps =
   | {
       requisitionId: string;
@@ -129,6 +150,9 @@ export function SelectLinkedAccountsModal({
       );
     },
   );
+  const [customStartingDates, setCustomStartingDates] = useState<
+    Record<string, StartingBalanceInfo>
+  >({});
   const { addOnBudgetAccountOption, addOffBudgetAccountOption } =
     useAddBudgetAccountOptions();
 
@@ -158,6 +182,14 @@ export function SelectLinkedAccountsModal({
         }
 
         // Finally link the matched account
+        const customSettings = customStartingDates[chosenExternalAccountId];
+        const startingDate =
+          customSettings?.date && customSettings.date.trim() !== ''
+            ? customSettings.date
+            : undefined;
+        const startingBalance =
+          customSettings?.amount != null ? customSettings.amount : undefined;
+
         if (propsWithSortedExternalAccounts.syncSource === 'simpleFin') {
           dispatch(
             linkAccountSimpleFin({
@@ -171,6 +203,8 @@ export function SelectLinkedAccountsModal({
                   ? chosenLocalAccountId
                   : undefined,
               offBudget,
+              startingDate,
+              startingBalance,
             }),
           );
         } else if (propsWithSortedExternalAccounts.syncSource === 'pluggyai') {
@@ -186,6 +220,8 @@ export function SelectLinkedAccountsModal({
                   ? chosenLocalAccountId
                   : undefined,
               offBudget,
+              startingDate,
+              startingBalance,
             }),
           );
         } else {
@@ -202,6 +238,8 @@ export function SelectLinkedAccountsModal({
                   ? chosenLocalAccountId
                   : undefined,
               offBudget,
+              startingDate,
+              startingBalance,
             }),
           );
         }
@@ -255,6 +293,33 @@ export function SelectLinkedAccountsModal({
     return localAccounts.find(acc => acc.id === chosenId);
   };
 
+  // Memoize default starting settings to avoid repeated calculations
+  const defaultStartingSettings = useMemo<StartingBalanceInfo>(
+    () => ({
+      date: subDays(currentDay(), 90),
+      amount: 0,
+    }),
+    [],
+  );
+
+  const getCustomStartingDate = (accountId: string) => {
+    if (customStartingDates[accountId]) {
+      return customStartingDates[accountId];
+    }
+    // Default to 90 days ago (matches server default)
+    return defaultStartingSettings;
+  };
+
+  const setCustomStartingDate = (
+    accountId: string,
+    settings: StartingBalanceInfo,
+  ) => {
+    setCustomStartingDates(prev => ({
+      ...prev,
+      [accountId]: settings,
+    }));
+  };
+
   const label = useMemo(() => {
     const s = new Set(draftLinkAccounts.values());
     if (s.has('linking') && s.has('unlinking')) {
@@ -325,6 +390,8 @@ export function SelectLinkedAccountsModal({
                   chosenAccount={getChosenAccount(account.account_id)}
                   unlinkedAccounts={unlinkedAccounts}
                   onSetLinkedAccount={onSetLinkedAccount}
+                  customStartingDate={getCustomStartingDate(account.account_id)}
+                  onSetCustomStartingDate={setCustomStartingDate}
                 />
               ))}
             </View>
@@ -333,35 +400,44 @@ export function SelectLinkedAccountsModal({
               style={{ ...styles.tableContainer, height: 300, flex: 'unset' }}
             >
               <TableHeader>
-                <Cell value={t('Institution to Sync')} width={175} />
-                <Cell value={t('Bank Account To Sync')} width={175} />
-                <Cell value={t('Balance')} width={80} />
+                <Cell value={t('Institution to Sync')} width={150} />
+                <Cell value={t('Bank Account To Sync')} width={150} />
+                <Cell value={t('Balance')} width={120} />
                 <Cell value={t('Account in Actual')} width="flex" />
-                <Cell value={t('Actions')} width={150} />
+                <Cell value={t('Starting Date')} width={120} />
+                <Cell value={t('Starting Balance')} width={120} />
+                <Cell value={t('Actions')} width={150} textAlign="center" />
               </TableHeader>
 
-              <Table<
-                SelectLinkedAccountsModalProps['externalAccounts'][number] & {
-                  id: string;
-                }
-              >
+              <Table<ExternalAccount & { id: string }>
                 items={propsWithSortedExternalAccounts.externalAccounts.map(
-                  account => ({
-                    ...account,
-                    id: account.account_id,
-                  }),
+                  acc => ({ ...acc, id: acc.account_id }),
                 )}
                 style={{ backgroundColor: theme.tableHeaderBackground }}
-                renderItem={({ item }) => (
-                  <View key={item.id}>
+                renderItem={({ item }) => {
+                  const chosenAccount = getChosenAccount(item.account_id);
+                  // Only show starting options for new accounts being created
+                  const shouldShowStartingOptions = isNewAccountOption(
+                    chosenAccount?.id,
+                    addOnBudgetAccountOption.id,
+                    addOffBudgetAccountOption.id,
+                  );
+
+                  return (
                     <TableRow
+                      key={item.id}
                       externalAccount={item}
-                      chosenAccount={getChosenAccount(item.account_id)}
+                      chosenAccount={chosenAccount}
                       unlinkedAccounts={unlinkedAccounts}
                       onSetLinkedAccount={onSetLinkedAccount}
+                      customStartingDate={getCustomStartingDate(
+                        item.account_id,
+                      )}
+                      onSetCustomStartingDate={setCustomStartingDate}
+                      showStartingOptions={shouldShowStartingOptions}
                     />
-                  </View>
-                )}
+                  );
+                }}
               />
             </View>
           )}
@@ -407,6 +483,11 @@ type ExternalAccount =
   | SyncServerSimpleFinAccount
   | SyncServerPluggyAiAccount;
 
+type StartingBalanceInfo = {
+  date: string;
+  amount: number;
+};
+
 type SharedAccountRowProps = {
   externalAccount: ExternalAccount;
   chosenAccount: { id: string; name: string } | undefined;
@@ -435,19 +516,64 @@ function getAvailableAccountOptions(
   return options;
 }
 
-type TableRowProps = SharedAccountRowProps;
+type TableRowProps = SharedAccountRowProps & {
+  customStartingDate: StartingBalanceInfo;
+  onSetCustomStartingDate: (
+    accountId: string,
+    settings: StartingBalanceInfo,
+  ) => void;
+  showStartingOptions: boolean;
+};
+
+function useStartingBalanceInfo(accountId: string | undefined) {
+  const [info, setInfo] = useState<StartingBalanceInfo | null>(null);
+
+  useEffect(() => {
+    if (!accountId) {
+      setInfo(null);
+      return;
+    }
+
+    const query = transactions(accountId)
+      .filter({ starting_balance_flag: true })
+      .select(['date', 'amount'])
+      .limit(1);
+
+    const live = liveQuery<StartingBalanceInfo>(query, {
+      onData: data => {
+        setInfo(data?.[0] ?? null);
+      },
+      onError: () => {
+        setInfo(null);
+      },
+    });
+
+    return () => {
+      live?.unsubscribe();
+    };
+  }, [accountId]);
+
+  return info;
+}
 
 function TableRow({
   externalAccount,
   chosenAccount,
   unlinkedAccounts,
   onSetLinkedAccount,
+  customStartingDate,
+  onSetCustomStartingDate,
+  showStartingOptions,
 }: TableRowProps) {
   const [focusedField, setFocusedField] = useState<string | null>(null);
   const { addOnBudgetAccountOption, addOffBudgetAccountOption } =
     useAddBudgetAccountOptions();
   const format = useFormat();
+  const dateFormat = useDateFormat() || 'MM/dd/yyyy';
   const { t } = useTranslation();
+  const startingBalanceInfo = useStartingBalanceInfo(
+    showStartingOptions ? undefined : chosenAccount?.id,
+  );
 
   const availableAccountOptions = getAvailableAccountOptions(
     unlinkedAccounts,
@@ -458,7 +584,8 @@ function TableRow({
 
   return (
     <Row style={{ backgroundColor: theme.tableBackground }}>
-      <Field width={175}>
+      {/* Institution to Sync */}
+      <Field width={150}>
         <Tooltip content={getInstitutionName(externalAccount)}>
           <View
             style={{
@@ -471,7 +598,8 @@ function TableRow({
           </View>
         </Tooltip>
       </Field>
-      <Field width={175}>
+      {/* Bank Account To Sync */}
+      <Field width={150}>
         <Tooltip content={externalAccount.name}>
           <View
             style={{
@@ -484,7 +612,8 @@ function TableRow({
           </View>
         </Tooltip>
       </Field>
-      <Field width={80}>
+      {/* Balance */}
+      <Field width={120} style={{ textAlign: 'right' }}>
         <PrivacyFilter>
           {externalAccount.balance != null ? (
             <FinancialText>
@@ -495,6 +624,7 @@ function TableRow({
           )}
         </PrivacyFilter>
       </Field>
+      {/* Account in Actual */}
       <Field
         width="flex"
         truncate={focusedField !== 'account'}
@@ -518,6 +648,47 @@ function TableRow({
           chosenAccount?.name
         )}
       </Field>
+      {showStartingOptions ? (
+        <StartingOptionsFields
+          accountId={externalAccount.account_id}
+          externalBalance={externalAccount.balance}
+          customStartingDate={customStartingDate}
+          onSetCustomStartingDate={onSetCustomStartingDate}
+          layout="inline"
+        />
+      ) : (
+        <>
+          {/* Starting Date */}
+          <Field width={120} truncate={false} style={{ textAlign: 'right' }}>
+            {startingBalanceInfo ? (
+              <Text
+                style={{
+                  color: theme.pageTextSubdued,
+                  fontStyle: 'italic',
+                }}
+              >
+                {formatDate(parseISO(startingBalanceInfo.date), dateFormat)}
+              </Text>
+            ) : null}
+          </Field>
+          {/* Starting Balance */}
+          <Field width={120} truncate={false} style={{ textAlign: 'right' }}>
+            {startingBalanceInfo ? (
+              <PrivacyFilter>
+                <FinancialText
+                  style={{
+                    color: theme.pageTextSubdued,
+                    fontStyle: 'italic',
+                  }}
+                >
+                  {format(startingBalanceInfo.amount, 'financial')}
+                </FinancialText>
+              </PrivacyFilter>
+            ) : null}
+          </Field>
+        </>
+      )}
+      {/* Actions */}
       <Field width={150}>
         {chosenAccount ? (
           <Button
@@ -558,18 +729,141 @@ function getInstitutionName(
   return '';
 }
 
-type AccountCardProps = SharedAccountRowProps;
+type StartingOptionsFieldsProps = {
+  accountId: string;
+  externalBalance: number | null | undefined;
+  customStartingDate: StartingBalanceInfo;
+  onSetCustomStartingDate: (
+    accountId: string,
+    settings: StartingBalanceInfo,
+  ) => void;
+  layout: 'inline' | 'stacked';
+};
+
+function StartingOptionsFields({
+  accountId,
+  externalBalance,
+  customStartingDate,
+  onSetCustomStartingDate,
+  layout,
+}: StartingOptionsFieldsProps) {
+  const zeroSign = externalBalance != null && externalBalance < 0 ? '-' : '+';
+
+  if (layout === 'inline') {
+    return (
+      <>
+        {/* Starting Date */}
+        <Field width={120} truncate={false}>
+          <Input
+            type="date"
+            value={customStartingDate.date}
+            onChange={e =>
+              onSetCustomStartingDate(accountId, {
+                ...customStartingDate,
+                date: e.target.value,
+              })
+            }
+            style={{ width: '100%' }}
+          />
+        </Field>
+        {/* Starting Balance */}
+        <Field width={120} truncate={false} style={{ textAlign: 'right' }}>
+          <AmountInput
+            value={customStartingDate.amount}
+            zeroSign={zeroSign}
+            onUpdate={amount =>
+              onSetCustomStartingDate(accountId, {
+                ...customStartingDate,
+                amount,
+              })
+            }
+            style={{ width: '100%' }}
+          />
+        </Field>
+      </>
+    );
+  }
+
+  return (
+    <View
+      style={{
+        marginTop: 8,
+        padding: '12px',
+        backgroundColor: theme.tableHeaderBackground,
+        borderRadius: 4,
+      }}
+    >
+      <View style={{ display: 'flex', flexDirection: 'column', gap: 10 }}>
+        <View>
+          <Text
+            style={{
+              marginBottom: 4,
+              fontSize: 13,
+              color: theme.pageTextSubdued,
+            }}
+          >
+            <Trans>Starting date:</Trans>
+          </Text>
+          <Input
+            type="date"
+            value={customStartingDate.date}
+            onChange={e =>
+              onSetCustomStartingDate(accountId, {
+                ...customStartingDate,
+                date: e.target.value,
+              })
+            }
+            style={{ width: '100%' }}
+          />
+        </View>
+        <View>
+          <Text
+            style={{
+              marginBottom: 4,
+              fontSize: 13,
+              color: theme.pageTextSubdued,
+            }}
+          >
+            <Trans>Balance on that date:</Trans>
+          </Text>
+          <AmountInput
+            value={customStartingDate.amount}
+            zeroSign={zeroSign}
+            onUpdate={amount =>
+              onSetCustomStartingDate(accountId, {
+                ...customStartingDate,
+                amount,
+              })
+            }
+            style={{ width: '100%' }}
+          />
+        </View>
+      </View>
+    </View>
+  );
+}
+
+type AccountCardProps = SharedAccountRowProps & {
+  customStartingDate: StartingBalanceInfo;
+  onSetCustomStartingDate: (
+    accountId: string,
+    settings: StartingBalanceInfo,
+  ) => void;
+};
 
 function AccountCard({
   externalAccount,
   chosenAccount,
   unlinkedAccounts,
   onSetLinkedAccount,
+  customStartingDate,
+  onSetCustomStartingDate,
 }: AccountCardProps) {
   const [focusedField, setFocusedField] = useState<string | null>(null);
   const { addOnBudgetAccountOption, addOffBudgetAccountOption } =
     useAddBudgetAccountOptions();
   const format = useFormat();
+  const dateFormat = useDateFormat() || 'MM/dd/yyyy';
   const { t } = useTranslation();
 
   const availableAccountOptions = getAvailableAccountOptions(
@@ -579,6 +873,16 @@ function AccountCard({
     addOffBudgetAccountOption,
   );
 
+  // Only show starting date options for new accounts being created
+  const shouldShowStartingOptions = isNewAccountOption(
+    chosenAccount?.id,
+    addOnBudgetAccountOption.id,
+    addOffBudgetAccountOption.id,
+  );
+  const startingBalanceInfo = useStartingBalanceInfo(
+    shouldShowStartingOptions ? undefined : chosenAccount?.id,
+  );
+
   return (
     <SpaceBetween
       direction="vertical"
@@ -655,6 +959,47 @@ function AccountCard({
         )}
       </SpaceBetween>
 
+      {!shouldShowStartingOptions && startingBalanceInfo && (
+        <View
+          style={{
+            fontSize: '0.9em',
+            color: theme.pageTextSubdued,
+            display: 'flex',
+            flexDirection: 'column',
+            gap: 4,
+          }}
+        >
+          <View style={{ display: 'flex', flexDirection: 'row', gap: 4 }}>
+            <Text style={{ color: theme.pageTextSubdued }}>
+              <Trans>Starting date:</Trans>
+            </Text>
+            <Text
+              style={{
+                color: theme.pageTextSubdued,
+                fontStyle: 'italic',
+              }}
+            >
+              {formatDate(parseISO(startingBalanceInfo.date), dateFormat)}
+            </Text>
+          </View>
+          <View style={{ display: 'flex', flexDirection: 'row', gap: 4 }}>
+            <Text style={{ color: theme.pageTextSubdued }}>
+              <Trans>Starting balance:</Trans>
+            </Text>
+            <PrivacyFilter>
+              <FinancialText
+                style={{
+                  color: theme.pageTextSubdued,
+                  fontStyle: 'italic',
+                }}
+              >
+                {format(startingBalanceInfo.amount, 'financial')}
+              </FinancialText>
+            </PrivacyFilter>
+          </View>
+        </View>
+      )}
+
       {focusedField === 'account' && (
         <View style={{ marginBottom: 12 }}>
           <Autocomplete
@@ -675,6 +1020,16 @@ function AccountCard({
         </View>
       )}
 
+      {shouldShowStartingOptions && (
+        <StartingOptionsFields
+          accountId={externalAccount.account_id}
+          externalBalance={externalAccount.balance}
+          customStartingDate={customStartingDate}
+          onSetCustomStartingDate={onSetCustomStartingDate}
+          layout="stacked"
+        />
+      )}
+
       {chosenAccount ? (
         <Button
           onPress={() => {
diff --git a/packages/loot-core/src/server/accounts/app.ts b/packages/loot-core/src/server/accounts/app.ts
index 26eb65b779..528e4694f9 100644
--- a/packages/loot-core/src/server/accounts/app.ts
+++ b/packages/loot-core/src/server/accounts/app.ts
@@ -38,6 +38,14 @@ import * as link from './link';
 import { getStartingBalancePayee } from './payees';
 import * as bankSync from './sync';
 
+// Shared base type for link account parameters
+type LinkAccountBaseParams = {
+  upgradingId?: AccountEntity['id'];
+  offBudget?: boolean;
+  startingDate?: string;
+  startingBalance?: number;
+};
+
 export type AccountHandlers = {
   'account-update': typeof updateAccount;
   'accounts-get': typeof getAccounts;
@@ -120,11 +128,11 @@ async function linkGoCardlessAccount({
   account,
   upgradingId,
   offBudget = false,
-}: {
+  startingDate,
+  startingBalance,
+}: LinkAccountBaseParams & {
   requisitionId: string;
   account: SyncServerGoCardlessAccount;
-  upgradingId?: AccountEntity['id'] | undefined;
-  offBudget?: boolean | undefined;
 }) {
   let id;
   const bank = await link.findOrCreateBank(account.institution, requisitionId);
@@ -170,6 +178,8 @@ async function linkGoCardlessAccount({
     id,
     account.account_id,
     bank.bank_id,
+    startingDate,
+    startingBalance,
   );
 
   connection.send('sync-event', {
@@ -184,10 +194,10 @@ async function linkSimpleFinAccount({
   externalAccount,
   upgradingId,
   offBudget = false,
-}: {
+  startingDate,
+  startingBalance,
+}: LinkAccountBaseParams & {
   externalAccount: SyncServerSimpleFinAccount;
-  upgradingId?: AccountEntity['id'] | undefined;
-  offBudget?: boolean | undefined;
 }) {
   let id;
 
@@ -240,6 +250,8 @@ async function linkSimpleFinAccount({
     id,
     externalAccount.account_id,
     bank.bank_id,
+    startingDate,
+    startingBalance,
   );
 
   await connection.send('sync-event', {
@@ -254,10 +266,10 @@ async function linkPluggyAiAccount({
   externalAccount,
   upgradingId,
   offBudget = false,
-}: {
+  startingDate,
+  startingBalance,
+}: LinkAccountBaseParams & {
   externalAccount: SyncServerPluggyAiAccount;
-  upgradingId?: AccountEntity['id'] | undefined;
-  offBudget?: boolean | undefined;
 }) {
   let id;
 
@@ -310,6 +322,8 @@ async function linkPluggyAiAccount({
     id,
     externalAccount.account_id,
     bank.bank_id,
+    startingDate,
+    startingBalance,
   );
 
   await connection.send('sync-event', {
@@ -845,24 +859,37 @@ type SyncError =
       internal?: string;
     };
 
+/**
+ * Type guard to check if an error is a BankSyncError.
+ * Handles both class instances and plain objects with the BankSyncError shape.
+ */
+function isBankSyncError(err: unknown): err is BankSyncError {
+  return (
+    err instanceof BankSyncError ||
+    (typeof err === 'object' &&
+      err !== null &&
+      'type' in err &&
+      err.type === 'BankSyncError')
+  );
+}
+
+/**
+ * Converts a sync error into a standardized SyncError response object.
+ */
 function handleSyncError(
   err: Error | PostError | BankSyncError,
   acct: db.DbAccount,
 ): SyncError {
-  // TODO: refactor bank sync logic to use BankSyncError properly
-  // oxlint-disable-next-line typescript/no-explicit-any
-  if (err instanceof BankSyncError || (err as any)?.type === 'BankSyncError') {
-    const error = err as BankSyncError;
-
+  if (isBankSyncError(err)) {
     const syncError = {
       type: 'SyncError',
       accountId: acct.id,
       message: 'Failed syncing account "' + acct.name + '."',
-      category: error.category,
-      code: error.code,
+      category: err.category,
+      code: err.code,
     };
 
-    if (error.category === 'RATE_LIMIT_EXCEEDED') {
+    if (err.category === 'RATE_LIMIT_EXCEEDED') {
       return {
         ...syncError,
         message: `Failed syncing account ${acct.name}. Rate limit exceeded. Please try again later.`,
diff --git a/packages/loot-core/src/server/accounts/sync.ts b/packages/loot-core/src/server/accounts/sync.ts
index 024b7e8161..8d4bca3afc 100644
--- a/packages/loot-core/src/server/accounts/sync.ts
+++ b/packages/loot-core/src/server/accounts/sync.ts
@@ -902,6 +902,8 @@ async function processBankSyncDownload(
   id,
   acctRow,
   initialSync = false,
+  customStartingBalance?: number,
+  customStartingDate?: string,
 ) {
   // If syncing an account from sync source it must not use strictIdChecking. This allows
   // the fuzzy search to match transactions where the import IDs are different. It is a known quirk
@@ -930,16 +932,17 @@ async function processBankSyncDownload(
     const { transactions } = download;
     let balanceToUse = currentBalance;
 
-    if (acctRow.account_sync_source === 'simpleFin') {
+    // Use custom starting balance if provided, otherwise calculate it
+    if (customStartingBalance !== undefined) {
+      balanceToUse = customStartingBalance;
+    } else if (acctRow.account_sync_source === 'simpleFin') {
       const previousBalance = transactions.reduce((total, trans) => {
         return (
           total - parseInt(trans.transactionAmount.amount.replace('.', ''))
         );
       }, currentBalance);
       balanceToUse = previousBalance;
-    }
-
-    if (acctRow.account_sync_source === 'pluggyai') {
+    } else if (acctRow.account_sync_source === 'pluggyai') {
       const currentBalance = download.startingBalance;
       const previousBalance = transactions.reduce(
         (total, trans) => total - trans.transactionAmount.amount * 100,
@@ -950,10 +953,15 @@ async function processBankSyncDownload(
 
     const oldestTransaction = transactions[transactions.length - 1];
 
-    const oldestDate =
-      transactions.length > 0
-        ? oldestTransaction.date
-        : monthUtils.currentDay();
+    // Use custom starting date if provided, otherwise use oldest transaction date or current day
+    let startingBalanceDate: string;
+    if (customStartingDate) {
+      startingBalanceDate = customStartingDate;
+    } else if (transactions.length > 0) {
+      startingBalanceDate = oldestTransaction.date;
+    } else {
+      startingBalanceDate = monthUtils.currentDay();
+    }
 
     const payee = await getStartingBalancePayee();
 
@@ -963,7 +971,7 @@ async function processBankSyncDownload(
         amount: balanceToUse,
         category: acctRow.offbudget === 0 ? payee.category : null,
         payee: payee.id,
-        date: oldestDate,
+        date: startingBalanceDate,
         cleared: true,
         starting_balance_flag: true,
       });
@@ -1014,10 +1022,13 @@ export async function syncAccount(
   id: string,
   acctId: string,
   bankId: string,
+  customStartingDate?: string,
+  customStartingBalance?: number,
 ) {
   const acctRow = await db.select('accounts', id);
 
-  const syncStartDate = await getAccountSyncStartDate(id);
+  const syncStartDate =
+    customStartingDate ?? (await getAccountSyncStartDate(id));
   const oldestTransaction = await getAccountOldestTransaction(id);
   const newAccount = oldestTransaction == null;
 
@@ -1041,7 +1052,14 @@ export async function syncAccount(
     );
   }
 
-  return processBankSyncDownload(download, id, acctRow, newAccount);
+  return processBankSyncDownload(
+    download,
+    id,
+    acctRow,
+    newAccount,
+    customStartingBalance,
+    customStartingDate,
+  );
 }
 
 export async function simpleFinBatchSync(
diff --git a/upcoming-release-notes/6629.md b/upcoming-release-notes/6629.md
new file mode 100644
index 0000000000..ddbbc72c9b
--- /dev/null
+++ b/upcoming-release-notes/6629.md
@@ -0,0 +1,6 @@
+---
+category: Enhancements
+authors: [StephenBrown2]
+---
+
+Add ability to specify custom starting date and balance when linking new bank sync accounts