diff --git a/src/kitUI/Cart/Cart.tsx b/src/kitUI/Cart/Cart.tsx
index 4a288ed..e72cfaa 100644
--- a/src/kitUI/Cart/Cart.tsx
+++ b/src/kitUI/Cart/Cart.tsx
@@ -1,5 +1,5 @@
 import theme from "@theme";
-import { Button, Paper, Box, Typography, TableHead, TableRow, TableCell, TableBody, Table, Tooltip } from "@mui/material";
+import { Button, Paper, Box, Typography, TableHead, TableRow, TableCell, TableBody, Table, Tooltip, Alert } from "@mui/material";
 import Input from "@kitUI/input";
 import { useCartStore } from "@root/stores/cart";
 import { useState } from "react";
@@ -10,17 +10,18 @@ import { calcCartData, createCartItem, findDiscountById, findDiscountFactor, for
 import { useTariffStore } from "@root/stores/tariffs";
 import { AnyDiscount, CartItemTotal } from "@root/model/cart";
 
+
 interface Props {
     selectedTariffs: GridSelectionModel;
 }
 
-// TODO реализовать правило "если взят готовый тариф, то кастомный на этот сервис сделать уже нельзя"
 export default function Cart({ selectedTariffs }: Props) {
     const tariffs = useTariffStore(store => store.tariffs);
     const discounts = useDiscountStore(store => store.discounts);
     const cartTotal = useCartStore(state => state.cartTotal);
     const setCartTotal = useCartStore(store => store.setCartTotal);
     const [couponField, setCouponField] = useState<string>("");
+    const [errorMessage, setErrorMessage] = useState<string | null>(null);
     // const [coupon, setCoupon] = useState<string | undefined>();
 
     const cartRows = cartTotal?.items.map(cartItemTotal => {
@@ -38,7 +39,7 @@ export default function Cart({ selectedTariffs }: Props) {
                                 discount={discount}
                                 cartItemTotal={cartItemTotal}
                             />
-                            {index < arr.length - (discount ? 0 : 1) &&
+                            {index < arr.length - (serviceDiscount ? 0 : 1) &&
                                 <span>,&nbsp;</span>
                             }
                         </span>
@@ -92,7 +93,15 @@ export default function Cart({ selectedTariffs }: Props) {
     function handleCalcCartClick() {
         const cartTariffs = tariffs.filter(tariff => selectedTariffs.includes(tariff.id));
         const cartItems = cartTariffs.map(tariff => createCartItem(tariff));
-        setCartTotal(calcCartData(testUser, cartItems, discounts, couponField));
+        const cartData = calcCartData(testUser, cartItems, discounts, couponField);
+
+        if (cartData instanceof Error) {
+            setErrorMessage(cartData.message);
+            return setCartTotal(null);
+        }
+
+        setErrorMessage(null);
+        setCartTotal(cartData);
     }
 
     return (
@@ -103,7 +112,9 @@ export default function Cart({ selectedTariffs }: Props) {
                 display: "flex",
                 flexDirection: "column",
                 alignItems: "center",
-                width: "100%"
+                width: "100%",
+                pb: "20px",
+                borderRadius: "4px",
             }}
         >
             <Typography variant="caption">
@@ -146,86 +157,96 @@ export default function Cart({ selectedTariffs }: Props) {
                 <Button onClick={handleCalcCartClick}>рассчитать</Button>
             </Paper>
 
-            <Table sx={{
-                width: "90%",
-                margin: "5px",
-                border: "2px solid",
-                borderColor: theme.palette.secondary.main,
-            }} aria-label="simple table">
-                <TableHead>
-                    <TableRow sx={{
-                        borderBottom: "2px solid",
-                        borderColor: theme.palette.grayLight.main,
-                        height: "100px"
-                    }}>
-                        <TableCell>
-                            <Typography
-                                variant="h4"
-                                sx={{ color: theme.palette.secondary.main }}
-                            >Имя</Typography>
-                        </TableCell>
-                        <TableCell>
-                            <Typography
-                                variant="h4"
-                                sx={{ color: theme.palette.secondary.main }}
-                            >Описание</Typography>
-                        </TableCell>
-                        <TableCell>
-                            <Typography
-                                variant="h4"
-                                sx={{ color: theme.palette.secondary.main }}
-                            >Скидки</Typography>
-                        </TableCell>
-                        <TableCell>
-                            <Typography
-                                variant="h4"
-                                sx={{ color: theme.palette.secondary.main }}
-                            >стоимость</Typography>
-                        </TableCell>
-                    </TableRow>
-                </TableHead>
-                <TableBody>
-                    {cartRows?.map(row => (
-                        <TableRow
-                            key={row.id}
-                            sx={{
+            {cartTotal?.items && cartTotal.items.length > 0 &&
+                <>
+                    <Table sx={{
+                        width: "90%",
+                        margin: "5px",
+                        border: "2px solid",
+                        borderColor: theme.palette.secondary.main,
+                    }} aria-label="simple table">
+                        <TableHead>
+                            <TableRow sx={{
                                 borderBottom: "2px solid",
                                 borderColor: theme.palette.grayLight.main,
-                            }}
-                        >
-                            <TableCell sx={{
-                                color: theme.palette.secondary.main,
-                            }}>{row.tariffName}</TableCell>
-                            <TableCell sx={{
-                                color: theme.palette.secondary.main,
-                            }}>{row.privilegeDesc}</TableCell>
-                            <TableCell sx={{
-                                color: theme.palette.secondary.main,
-                            }}>{row.envolvedDiscounts}</TableCell>
-                            <TableCell sx={{
-                                color: theme.palette.secondary.main,
-                            }}>{row.price.toFixed(2)} ₽</TableCell>
-                        </TableRow>
-                    ))}
-                </TableBody>
-            </Table>
+                                height: "100px"
+                            }}>
+                                <TableCell>
+                                    <Typography
+                                        variant="h4"
+                                        sx={{ color: theme.palette.secondary.main }}
+                                    >Имя</Typography>
+                                </TableCell>
+                                <TableCell>
+                                    <Typography
+                                        variant="h4"
+                                        sx={{ color: theme.palette.secondary.main }}
+                                    >Описание</Typography>
+                                </TableCell>
+                                <TableCell>
+                                    <Typography
+                                        variant="h4"
+                                        sx={{ color: theme.palette.secondary.main }}
+                                    >Скидки</Typography>
+                                </TableCell>
+                                <TableCell>
+                                    <Typography
+                                        variant="h4"
+                                        sx={{ color: theme.palette.secondary.main }}
+                                    >стоимость</Typography>
+                                </TableCell>
+                            </TableRow>
+                        </TableHead>
+                        <TableBody>
+                            {cartRows?.map(row => (
+                                <TableRow
+                                    key={row.id}
+                                    sx={{
+                                        borderBottom: "2px solid",
+                                        borderColor: theme.palette.grayLight.main,
+                                    }}
+                                >
+                                    <TableCell sx={{
+                                        color: theme.palette.secondary.main,
+                                    }}>{row.tariffName}</TableCell>
+                                    <TableCell sx={{
+                                        color: theme.palette.secondary.main,
+                                    }}>{row.privilegeDesc}</TableCell>
+                                    <TableCell sx={{
+                                        color: theme.palette.secondary.main,
+                                    }}>{row.envolvedDiscounts}</TableCell>
+                                    <TableCell sx={{
+                                        color: theme.palette.secondary.main,
+                                    }}>{row.price.toFixed(2)} ₽</TableCell>
+                                </TableRow>
+                            ))}
+                        </TableBody>
+                    </Table>
 
-            <Typography id="transition-modal-title" variant="h6" sx={{
-                fontWeight: "normal",
-                textAlign: "center",
-                marginTop: "15px",
-                fontSize: "16px"
-            }}>
-                Скидки корзины: {envolvedCartDiscountsElement}
-            </Typography>
+                    <Typography id="transition-modal-title" variant="h6" sx={{
+                        fontWeight: "normal",
+                        textAlign: "center",
+                        marginTop: "15px",
+                        fontSize: "16px"
+                    }}>
+                        Скидки корзины: {envolvedCartDiscountsElement}
+                    </Typography>
 
-            <Typography id="transition-modal-title" variant="h6" sx={{
-                fontWeight: "normal",
-                textAlign: "center",
-                marginTop: "10px"
-            }}>
-                ИТОГО: <span>{cartTotal?.totalPrice.toFixed(2)} ₽</span>
-            </Typography>
+                    <Typography id="transition-modal-title" variant="h6" sx={{
+                        fontWeight: "normal",
+                        textAlign: "center",
+                        marginTop: "10px"
+                    }}>
+                        ИТОГО: <span>{cartTotal?.totalPrice.toFixed(2)} ₽</span>
+                    </Typography>
+                </>
+            }
+
+            {errorMessage !== null &&
+                <Alert variant="filled" severity="error" sx={{ mt: "20px" }}>
+                    {errorMessage}
+                </Alert>
+            }
 
         </Box>
     );
diff --git a/src/kitUI/Cart/calc.test.ts b/src/kitUI/Cart/calc.test.ts
index b182ad5..1451441 100644
--- a/src/kitUI/Cart/calc.test.ts
+++ b/src/kitUI/Cart/calc.test.ts
@@ -1,4 +1,4 @@
-import { CartItem } from "../../model/cart";
+import { CartItem, CartTotal } from "../../model/cart";
 import { SERVICE_LIST, Tariff } from "../../model/tariff";
 import { User } from "../../model/user";
 import { exampleCartValues, TestCase } from "../../stores/mocks/exampleCartValues";
@@ -12,7 +12,7 @@ describe("cart tests", () => {
     it("без скидок", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[0]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -36,7 +36,7 @@ describe("cart tests", () => {
             );
         });
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -60,7 +60,7 @@ describe("cart tests", () => {
             );
         });
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -84,7 +84,7 @@ describe("cart tests", () => {
             );
         });
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -108,7 +108,7 @@ describe("cart tests", () => {
             );
         });
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discountsWithoutTemplategen) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -124,7 +124,7 @@ describe("cart tests", () => {
     it("история про то, как скидки за привилегии помешали получить скидку за сервис", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[5]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -140,7 +140,7 @@ describe("cart tests", () => {
     it("то же что и выше, но без лояльности", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[6]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -156,7 +156,7 @@ describe("cart tests", () => {
     it("история про то, как получилось получить скидку за сервис", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[7]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -172,7 +172,7 @@ describe("cart tests", () => {
     it("две скидки за сервис", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[8]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -188,7 +188,7 @@ describe("cart tests", () => {
     it("юзер использовал промокод id33. он заменяет скидку на p6 собой. в один момент времени может быть активирован только 1 промокод, т.е. после активации следующего, предыдущий заменяется. но в промокоде может быть несколько скидок. промокоды имеют скидки только на привелеги", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[9]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts, "ABCD");
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts, "ABCD") as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -204,7 +204,7 @@ describe("cart tests", () => {
     it("юзер подтвердил свой статус НКО, поэтому, не смотря на то что он достиг по лояльности уровня скидки id2, она не применилась, а применилась id32", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[10]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
@@ -220,7 +220,7 @@ describe("cart tests", () => {
     it("case 12", () => {
         const testCase = prepareTestCase(exampleCartValues.testCases[11]);
 
-        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts);
+        const cartTotal = calcCartData(testCase.user, testCase.cartItems, discounts) as CartTotal;
         const allEnvolvedDiscounts: string[] = [...cartTotal.envolvedCartDiscountIds];
         cartTotal.items.forEach(cartItem => {
             allEnvolvedDiscounts.push(...cartItem.envolvedDiscountIds);
diff --git a/src/kitUI/Cart/calc.ts b/src/kitUI/Cart/calc.ts
index 889fcc8..a74a48f 100644
--- a/src/kitUI/Cart/calc.ts
+++ b/src/kitUI/Cart/calc.ts
@@ -8,7 +8,28 @@ export function calcCartData(
     cartItems: CartItem[],
     discounts: AnyDiscount[],
     coupon?: string,
-): CartTotal {
+): CartTotal | Error | null {
+    let isIncompatibleTariffs = false;
+
+    const defaultTariffTypePresent: { [Key in ServiceType]: boolean } = {
+        dwarfener: false,
+        squiz: false,
+        templategen: false,
+    };
+
+    cartItems.forEach(cartItem => {
+        if (cartItem.tariff.customPricePerUnit === undefined) return defaultTariffTypePresent[cartItem.tariff.privilege.serviceKey] = true;
+
+        if (
+            defaultTariffTypePresent[cartItem.tariff.privilege.serviceKey] &&
+            cartItem.tariff.customPricePerUnit !== undefined
+        ) isIncompatibleTariffs = true;
+    });
+
+    if (isIncompatibleTariffs) return new Error("Если взят готовый тариф, то кастомный на этот сервис сделать уже нельзя");
+
+    if (!cartItems.length) return null;
+
     const cartTotal: CartTotal = {
         items: [],
         totalPrice: 0,
diff --git a/src/stores/cart.ts b/src/stores/cart.ts
index 9673ca8..a0d7e69 100644
--- a/src/stores/cart.ts
+++ b/src/stores/cart.ts
@@ -5,7 +5,7 @@ import { CartTotal } from "@root/model/cart";
 
 interface CartStore {
     cartTotal: CartTotal | null;
-    setCartTotal: (newCartTotal: CartTotal) => void;
+    setCartTotal: (newCartTotal: CartTotal | null) => void;
 }
 
 export const useCartStore = create<CartStore>()(