diff --git a/src/api/custom/hello-techno/receipt-issuing-order.ts b/src/api/custom/hello-techno/receipt-issuing-order.ts
index 290fee1..44dc879 100644
--- a/src/api/custom/hello-techno/receipt-issuing-order.ts
+++ b/src/api/custom/hello-techno/receipt-issuing-order.ts
@@ -16,6 +16,7 @@ export type CreateReceiptIssuingOrderRequest = {
   adjust_seq_no?: string | number;
   receipt_use_date: Date | null;
   receipt_amount: string | number;
+  tax_amount: string | number;
   memo?: string;
   sms_phone_number: string;
 };
@@ -43,6 +44,8 @@ export type ReceiptIssuingOrderHTCustom = {
   customer_name: string;
   parking_name: string;
   adjust_seq_no?: number;
+  tax_rate?: number;
+  tax_amount?: number;
 } & ReceiptIssuingOrder;
 
 export type ReceiptIssuingOrdersRequest = {
diff --git a/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/create.tsx b/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/create.tsx
index d291576..e8146c1 100644
--- a/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/create.tsx
+++ b/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/create.tsx
@@ -136,6 +136,7 @@ export default function ReceiptIssuingOrderCreate() {
       adjust_seq_no: formData.adjustSeqNo,
       receipt_use_date: formData.date,
       receipt_amount: formData.amount,
+      tax_amount: formData.tax_amount,
       sms_phone_number: formData.address,
       memo: formData.memo,
     });
diff --git a/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/detail.tsx b/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/detail.tsx
index 75cb215..3a2dc15 100644
--- a/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/detail.tsx
+++ b/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/detail.tsx
@@ -112,6 +112,13 @@ export default function ReceiptIssuingOrderDetail() {
           ? order.receipt_amount.toLocaleString() + "円"
           : "-",
       },
+      {
+        title: "消費税(内税)",
+        value:
+          isNumber(order.tax_amount) && isNumber(order.tax_rate)
+            ? order.tax_amount.toLocaleString() + "円(" + order.tax_rate + "%)"
+            : "-",
+      },
       { title: "備考", value: order.memo },
     ];
   }, [order]);
diff --git a/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/hooks/useInputReceiptStep.tsx b/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/hooks/useInputReceiptStep.tsx
index d48b21a..611d51a 100644
--- a/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/hooks/useInputReceiptStep.tsx
+++ b/src/pages/dashboard/receipt-issuing-order/custom/hello-techno/hooks/useInputReceiptStep.tsx
@@ -16,6 +16,7 @@ import RHFDatePicker from "components/hook-form/RHFDatePicker";
 import { useEffect, useMemo, useState } from "react";
 import { useForm } from "react-hook-form";
 import { dateTimeParse } from "utils/datetime";
+import { calcInnerTax } from "utils/tax";
 import * as Yup from "yup";
 
 type AreaBoxProps = {
@@ -32,6 +33,7 @@ function AreaBox({ title, children }: AreaBoxProps) {
 
 type FormProps = {
   amount: string;
+  tax_amount: string;
   date: Date | null;
   memo: string;
 };
@@ -46,6 +48,7 @@ export default function useInputReceiptStep({ onNext, onPrev }: Props) {
   const form = useForm<FormProps>({
     defaultValues: {
       amount: "",
+      tax_amount: "",
       date: null,
       memo: "",
     },
@@ -55,6 +58,7 @@ export default function useInputReceiptStep({ onNext, onPrev }: Props) {
           .required("必須項目です")
           .typeError("正しく入力してください"),
         amount: Yup.number().required("必須項目です"),
+        tax_amount: Yup.number().required("必須項目です"),
         memo: Yup.string().nullable(),
       })
     ),
@@ -77,6 +81,17 @@ export default function useInputReceiptStep({ onNext, onPrev }: Props) {
     _setAdjustData(data);
   };
 
+  const canCalcTax = useMemo(() => {
+    return !adjustData;
+  }, [adjustData]);
+
+  const calcTax = () => {
+    if (!canCalcTax) return;
+    const amount = Number(form.getValues("amount"));
+    if (!amount) return;
+    form.setValue("tax_amount", String(calcInnerTax(amount)));
+  };
+
   const readOnly = useMemo(() => {
     return adjustData !== null;
   }, [adjustData]);
@@ -99,6 +114,27 @@ export default function useInputReceiptStep({ onNext, onPrev }: Props) {
             readOnly={readOnly}
           />
         </AreaBox>
+        <AreaBox title="消費税(内税)">
+          <Stack direction="row" spacing={2}>
+            <RHFTextField
+              type="number"
+              name="tax_amount"
+              size="small"
+              InputProps={{
+                endAdornment: (
+                  <div style={{ color: "black !important" }}>円</div>
+                ),
+              }}
+              sx={{ maxWidth: 150 }}
+              readOnly={readOnly}
+            />
+            {canCalcTax && (
+              <Button onClick={calcTax} variant="text">
+                計算
+              </Button>
+            )}
+          </Stack>
+        </AreaBox>
         <AreaBox title="メモ">
           <RHFTextField name="memo" size="small" multiline rows={3} />
         </AreaBox>
@@ -116,9 +152,11 @@ export default function useInputReceiptStep({ onNext, onPrev }: Props) {
   useEffect(() => {
     if (adjustData) {
       form.setValue("amount", String(adjustData.amount));
+      form.setValue("tax_amount", String(adjustData.tax_charge));
       form.setValue("date", dateTimeParse(adjustData.adjust_datetime));
     } else {
       form.setValue("amount", "");
+      form.setValue("tax_amount", "");
       form.setValue("date", null);
     }
   }, [adjustData]);
diff --git a/src/utils/tax.ts b/src/utils/tax.ts
new file mode 100644
index 0000000..71b023b
--- /dev/null
+++ b/src/utils/tax.ts
@@ -0,0 +1,11 @@
+export const TAX_RATE_DEFAULT = 0.1;
+
+/**
+ * 内税計算
+ */
+export function calcInnerTax(
+  totalAmount: number,
+  rate: number = TAX_RATE_DEFAULT
+) {
+  return Math.floor((totalAmount * rate) / (1 + rate));
+}