diff --git a/app/(dashboard)/settings/page.tsx b/app/(dashboard)/settings/page.tsx
index 15878845..a78c6096 100644
--- a/app/(dashboard)/settings/page.tsx
+++ b/app/(dashboard)/settings/page.tsx
@@ -56,6 +56,8 @@ export default function SettingsPage() {
   const hasMcpExtension = ENABLED_EXTENSION_IDS.has('mcp-server')
   const [bankConnectionError, setBankConnectionError] = useState<string | null>(null)
   const [bankgiroError, setBankgiroError] = useState<string | null>(null)
+  const [clearingError, setClearingError] = useState<string | null>(null)
+  const [accountNumberError, setAccountNumberError] = useState<string | null>(null)
   const [showDeleteDialog, setShowDeleteDialog] = useState(false)
   const [deleteConfirmText, setDeleteConfirmText] = useState('')
   const [isDeleting, setIsDeleting] = useState(false)
@@ -148,10 +150,40 @@ export default function SettingsPage() {
     e.preventDefault()
     if (!settings) return
 
-    setIsSaving(true)
-
     const formData = new FormData(e.currentTarget)
 
+    // Validate bank fields before saving
+    const clearingVal = (formData.get('clearing_number') as string || '').trim()
+    const accountVal = (formData.get('account_number') as string || '').trim()
+    const bankgiroVal = (formData.get('bankgiro') as string || '').trim()
+
+    let hasErrors = false
+
+    if (clearingVal && !/^\d{4,5}$/.test(clearingVal)) {
+      setClearingError('Clearingnummer måste vara 4-5 siffror')
+      hasErrors = true
+    } else {
+      setClearingError(null)
+    }
+
+    if (accountVal && !/^\d{6,12}$/.test(accountVal)) {
+      setAccountNumberError('Kontonummer måste vara 6-12 siffror')
+      hasErrors = true
+    } else {
+      setAccountNumberError(null)
+    }
+
+    if (bankgiroVal && !validateBankgiroNumber(bankgiroVal)) {
+      setBankgiroError('Ogiltigt bankgironummer (7-8 siffror med kontrollsiffra)')
+      hasErrors = true
+    } else {
+      setBankgiroError(null)
+    }
+
+    if (hasErrors) return
+
+    setIsSaving(true)
+
     // Disabled inputs are excluded from FormData by the browser,
     // so only include company_name/org_number when not locked
     const updates: Record<string, unknown> = {
@@ -392,6 +424,8 @@ export default function SettingsPage() {
                     <Input
                       id="bank_name"
                       name="bank_name"
+                      placeholder="t.ex. Nordea"
+                      maxLength={100}
                       defaultValue={settings?.bank_name || ''}
                     />
                   </div>
@@ -400,16 +434,58 @@ export default function SettingsPage() {
                     <Input
                       id="clearing_number"
                       name="clearing_number"
+                      inputMode="numeric"
+                      placeholder="XXXX"
+                      maxLength={5}
                       defaultValue={settings?.clearing_number || ''}
+                      onChange={(e) => {
+                        e.target.value = e.target.value.replace(/\D/g, '')
+                      }}
+                      onBlur={(e) => {
+                        const val = e.target.value.trim()
+                        if (!val) {
+                          setClearingError(null)
+                          return
+                        }
+                        if (!/^\d{4,5}$/.test(val)) {
+                          setClearingError('Clearingnummer måste vara 4-5 siffror')
+                        } else {
+                          setClearingError(null)
+                        }
+                      }}
                     />
+                    {clearingError && (
+                      <p className="text-xs text-destructive">{clearingError}</p>
+                    )}
                   </div>
                   <div className="space-y-2">
                     <Label htmlFor="account_number">Kontonummer</Label>
                     <Input
                       id="account_number"
                       name="account_number"
+                      inputMode="numeric"
+                      placeholder="XXXXXXX"
+                      maxLength={12}
                       defaultValue={settings?.account_number || ''}
+                      onChange={(e) => {
+                        e.target.value = e.target.value.replace(/\D/g, '')
+                      }}
+                      onBlur={(e) => {
+                        const val = e.target.value.trim()
+                        if (!val) {
+                          setAccountNumberError(null)
+                          return
+                        }
+                        if (!/^\d{6,12}$/.test(val)) {
+                          setAccountNumberError('Kontonummer måste vara 6-12 siffror')
+                        } else {
+                          setAccountNumberError(null)
+                        }
+                      }}
                     />
+                    {accountNumberError && (
+                      <p className="text-xs text-destructive">{accountNumberError}</p>
+                    )}
                   </div>
                 </div>
                 <div className="max-w-xs space-y-2">
diff --git a/components/bookkeeping/AccountCombobox.tsx b/components/bookkeeping/AccountCombobox.tsx
index 04fbc738..8160b701 100644
--- a/components/bookkeeping/AccountCombobox.tsx
+++ b/components/bookkeeping/AccountCombobox.tsx
@@ -104,7 +104,6 @@ export default function AccountCombobox({ value, accounts, onChange }: AccountCo
       onChange(accountNumber)
       setSearch(accountNumber)
       setIsOpen(false)
-      inputRef.current?.blur()
     },
     [onChange]
   )
diff --git a/lib/api/schemas.ts b/lib/api/schemas.ts
index 7fb62a09..807220b6 100644
--- a/lib/api/schemas.ts
+++ b/lib/api/schemas.ts
@@ -369,10 +369,10 @@ export const UpdateSettingsSchema = z.object({
   moms_period: MomsPeriodSchema.nullable().optional(),
   fiscal_year_start_month: z.number().int().min(1).max(12).optional(),
   preliminary_tax_monthly: z.number().nullable().optional(),
-  bank_name: z.string().optional(),
-  clearing_number: z.string().optional(),
-  account_number: z.string().optional(),
-  bankgiro: z.string().nullable().optional(),
+  bank_name: z.string().max(100, 'Banknamn får vara max 100 tecken').optional(),
+  clearing_number: z.string().regex(/^\d{4,5}$/, 'Clearingnummer måste vara 4-5 siffror').optional().or(z.literal('')),
+  account_number: z.string().regex(/^\d{6,12}$/, 'Kontonummer måste vara 6-12 siffror').optional().or(z.literal('')),
+  bankgiro: z.string().regex(/^(\d{3,4}-\d{4}|\d{7,8})$/, 'Ogiltigt bankgironummer (7-8 siffror)').nullable().optional().or(z.literal('')),
   iban: z.string().optional(),
   bic: z.string().optional(),
   accounting_method: AccountingMethodSchema.optional(),