diff --git a/src/app/groups/[groupId]/expenses/create-from-receipt-button.tsx b/src/app/groups/[groupId]/expenses/create-from-receipt-button.tsx
index c157cc9..dab04a1 100644
--- a/src/app/groups/[groupId]/expenses/create-from-receipt-button.tsx
+++ b/src/app/groups/[groupId]/expenses/create-from-receipt-button.tsx
@@ -26,7 +26,7 @@ import {
 import { ToastAction } from '@/components/ui/toast'
 import { useToast } from '@/components/ui/use-toast'
 import { useMediaQuery } from '@/lib/hooks'
-import { formatCurrency, formatExpenseDate } from '@/lib/utils'
+import { formatCurrency, formatExpenseDate, formatFileSize } from '@/lib/utils'
 import { Category } from '@prisma/client'
 import { ChevronRight, FileQuestion, Loader2, Receipt } from 'lucide-react'
 import { getImageData, usePresignedUpload } from 'next-s3-upload'
@@ -40,6 +40,8 @@ type Props = {
   categories: Category[]
 }
 
+const MAX_FILE_SIZE = 5 * 1024 ** 2
+
 export function CreateFromReceiptButton({
   groupId,
   groupCurrency,
@@ -56,6 +58,17 @@ export function CreateFromReceiptButton({
   const isDesktop = useMediaQuery('(min-width: 640px)')
 
   const handleFileChange = async (file: File) => {
+    if (file.size > MAX_FILE_SIZE) {
+      toast({
+        title: 'The file is too big',
+        description: `The maximum file size you can upload is ${formatFileSize(
+          MAX_FILE_SIZE,
+        )}. Yours is ${formatFileSize(file.size)}.`,
+        variant: 'destructive',
+      })
+      return
+    }
+
     const upload = async () => {
       try {
         setPending(true)
diff --git a/src/components/expense-documents-input.tsx b/src/components/expense-documents-input.tsx
index 7b69a6d..ae8a272 100644
--- a/src/components/expense-documents-input.tsx
+++ b/src/components/expense-documents-input.tsx
@@ -17,6 +17,7 @@ import { ToastAction } from '@/components/ui/toast'
 import { useToast } from '@/components/ui/use-toast'
 import { randomId } from '@/lib/api'
 import { ExpenseFormValues } from '@/lib/schemas'
+import { formatFileSize } from '@/lib/utils'
 import { Loader2, Plus, Trash, X } from 'lucide-react'
 import { getImageData, usePresignedUpload } from 'next-s3-upload'
 import Image from 'next/image'
@@ -27,12 +28,25 @@ type Props = {
   updateDocuments: (documents: ExpenseFormValues['documents']) => void
 }
 
+const MAX_FILE_SIZE = 5 * 1024 ** 2
+
 export function ExpenseDocumentsInput({ documents, updateDocuments }: Props) {
   const [pending, setPending] = useState(false)
   const { FileInput, openFileDialog, uploadToS3 } = usePresignedUpload() // use presigned uploads to addtionally support providers other than AWS
   const { toast } = useToast()
 
   const handleFileChange = async (file: File) => {
+    if (file.size > MAX_FILE_SIZE) {
+      toast({
+        title: 'The file is too big',
+        description: `The maximum file size you can upload is ${formatFileSize(
+          MAX_FILE_SIZE,
+        )}. Yours is ${formatFileSize(file.size)}.`,
+        variant: 'destructive',
+      })
+      return
+    }
+
     const upload = async () => {
       try {
         setPending(true)
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index 2ce486c..06d1989 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -29,3 +29,16 @@ export function formatCurrency(currency: string, amount: number) {
   const formattedAmount = format.format(amount / 100)
   return `${currency} ${formattedAmount}`
 }
+
+export function formatFileSize(size: number) {
+  const formatNumber = (num: number) =>
+    num.toLocaleString('en-US', {
+      minimumFractionDigits: 0,
+      maximumFractionDigits: 1,
+    })
+
+  if (size > 1024 ** 3) return `${formatNumber(size / 1024 ** 3)} GB`
+  if (size > 1024 ** 2) return `${formatNumber(size / 1024 ** 2)} MB`
+  if (size > 1024) return `${formatNumber(size / 1024)} kB`
+  return `${formatNumber(size)} B`
+}