diff --git a/src/record/delete/index.ts b/src/record/delete/index.ts
index 7a01f04ee6..3261d039b4 100644
--- a/src/record/delete/index.ts
+++ b/src/record/delete/index.ts
@@ -8,6 +8,7 @@ import { deleteByRecordNumber } from "./usecases/deleteByRecordNumber";
 import { logger } from "../../utils/log";
 import type { SupportedImportEncoding } from "../../utils/file";
 import { readFile } from "../../utils/file";
+import { isMismatchEncoding } from "../../utils/encoding";
 import { parseRecords } from "./parsers";
 import { RunError } from "../error";
 
@@ -41,6 +42,10 @@ const deleteRecordsByFile = async (
   filePath: string,
   encoding?: SupportedImportEncoding,
 ): Promise<void> => {
+  if (encoding) {
+    await validateEncoding(filePath, encoding);
+  }
+
   const recordNumbers = await getRecordNumbersFromFile(
     apiClient,
     app,
@@ -85,3 +90,14 @@ const getRecordNumberFieldCode = (
 
   return recordNumberFieldCode;
 };
+
+const validateEncoding: (
+  filePath: string,
+  encoding: SupportedImportEncoding,
+) => Promise<void> = async (filePath, encoding) => {
+  if (await isMismatchEncoding(filePath, encoding)) {
+    throw new Error(
+      `Failed to decode the specified CSV file.\nThe specified encoding (${encoding}) might mismatch the actual encoding of the CSV file.`,
+    );
+  }
+};
diff --git a/src/record/import/index.ts b/src/record/import/index.ts
index 35cfb5b1ee..b4cadfce05 100644
--- a/src/record/import/index.ts
+++ b/src/record/import/index.ts
@@ -10,6 +10,7 @@ import { userSelected } from "./schema/transformers/userSelected";
 import { logger } from "../../utils/log";
 import { LocalRecordRepositoryFromStream } from "./repositories/localRecordRepositoryFromStream";
 import { RunError } from "../error";
+import { isMismatchEncoding } from "../../utils/encoding";
 
 export type Options = {
   app: string;
@@ -34,8 +35,10 @@ export const run: (
       ...restApiClientOptions
     } = argv;
 
+    if (encoding) {
+      await validateEncoding(filePath, encoding);
+    }
     const apiClient = buildRestAPIClient(restApiClientOptions);
-
     const fieldsJson = await apiClient.app.getFormFields({ app });
     const schema = createSchema(
       fieldsJson,
@@ -80,3 +83,14 @@ export const run: (
     process.exit(1);
   }
 };
+
+const validateEncoding: (
+  filePath: string,
+  encoding: SupportedImportEncoding,
+) => Promise<void> = async (filePath, encoding) => {
+  if (await isMismatchEncoding(filePath, encoding)) {
+    throw new Error(
+      `Failed to decode the specified CSV file.\nThe specified encoding (${encoding}) might mismatch the actual encoding of the CSV file.`,
+    );
+  }
+};
diff --git a/src/utils/__tests__/encoding.test.ts b/src/utils/__tests__/encoding.test.ts
new file mode 100644
index 0000000000..7c01de9767
--- /dev/null
+++ b/src/utils/__tests__/encoding.test.ts
@@ -0,0 +1,14 @@
+import { isMismatchEncoding } from "../encoding";
+import path from "path";
+
+describe("isMismatchEncoding", () => {
+  it("should detect the mismatch encoding correctly", async () => {
+    const inputSJISFile = path.join(__dirname, "./fixtures/input_sjis.csv");
+    expect(await isMismatchEncoding(inputSJISFile, "sjis")).toBe(false);
+    expect(await isMismatchEncoding(inputSJISFile, "utf8")).toBe(true);
+
+    const inputUTF8File = path.join(__dirname, "./fixtures/input_utf8.csv");
+    expect(await isMismatchEncoding(inputUTF8File, "sjis")).toBe(true);
+    expect(await isMismatchEncoding(inputUTF8File, "utf8")).toBe(false);
+  });
+});
diff --git a/src/utils/encoding.ts b/src/utils/encoding.ts
new file mode 100644
index 0000000000..c75077df21
--- /dev/null
+++ b/src/utils/encoding.ts
@@ -0,0 +1,54 @@
+import fs from "fs";
+import iconv from "iconv-lite";
+import readline from "readline";
+import { extractFileFormat } from "./file";
+import type { SupportedImportEncoding } from "./file";
+import { Transform } from "stream";
+
+export const isMismatchEncoding = async (
+  filePath: string,
+  encoding: SupportedImportEncoding,
+): Promise<boolean> => {
+  const format = extractFileFormat(filePath);
+  switch (format) {
+    case "csv":
+      return isMismatchEncodingOfCsvFile(filePath, encoding);
+  }
+
+  return false;
+};
+
+const isMismatchEncodingOfCsvFile: (
+  filePath: string,
+  encoding: SupportedImportEncoding,
+) => Promise<boolean> = async (filePath, encoding) => {
+  const decodedFirstLine = await getDecodedFirstLine(filePath, encoding);
+  return containsUntranslatableChars(decodedFirstLine);
+};
+
+const getDecodedFirstLine: (
+  filePath: string,
+  encoding: SupportedImportEncoding,
+) => Promise<string> = async (filePath, encoding) => {
+  const stream = fs.createReadStream(filePath);
+  const decodedStream = stream.pipe(
+    Transform.from(iconv.decodeStream(encoding)),
+  );
+  stream.on("error", (e) => {
+    decodedStream.destroy(e);
+  });
+
+  const reader = readline.createInterface({
+    input: decodedStream,
+  });
+
+  const { value: firstRow } = await reader[Symbol.asyncIterator]().next();
+  reader.close();
+
+  return firstRow;
+};
+
+const containsUntranslatableChars: (content: string) => boolean = (content) => {
+  const untranslatableChars = ["�", "?"];
+  return untranslatableChars.some((char) => content.includes(char));
+};