diff --git a/server/shell/g1.sh b/server/shell/g1.sh
index 1fe4a6a59..68777cac2 100755
--- a/server/shell/g1.sh
+++ b/server/shell/g1.sh
@@ -4,8 +4,8 @@
 source "$(dirname "$0")/config.sh"
 
 # If contains setup then run $MOCHA_SETUP
-  MOCHA_PARALLEL=true $MOCHA_SETUP
 # if [[ "$2" == *"setup"* ]]; then
+#   MOCHA_PARALLEL=true $MOCHA_SETUP
 # fi
 
 $MOCHA_CMD \
@@ -16,6 +16,7 @@ $MOCHA_CMD \
 
 $MOCHA_CMD \
 'tests/attach/entities/*.ts' \
-'tests/attach/free/*.ts'
+'tests/attach/free/*.ts'\
+'tests/attach/addOn/*.ts'
 
 # 'tests/attach/basic/basic2.ts' \
\ No newline at end of file
diff --git a/server/src/internal/customers/attach/attachFunctions/upgradeSameIntFlow/handleUpgradeSameInt.ts b/server/src/internal/customers/attach/attachFunctions/upgradeSameIntFlow/handleUpgradeSameInt.ts
index 6a04c0187..7795a5582 100644
--- a/server/src/internal/customers/attach/attachFunctions/upgradeSameIntFlow/handleUpgradeSameInt.ts
+++ b/server/src/internal/customers/attach/attachFunctions/upgradeSameIntFlow/handleUpgradeSameInt.ts
@@ -2,7 +2,10 @@ import {
   AttachParams,
   AttachResultSchema,
 } from "@/internal/customers/cusProducts/AttachParams.js";
-import { attachParamToCusProducts } from "../../attachUtils/convertAttachParams.js";
+import {
+  attachParamsToCurCusProduct,
+  attachParamToCusProducts,
+} from "../../attachUtils/convertAttachParams.js";
 import { CusProductService } from "@/internal/customers/cusProducts/CusProductService.js";
 import { createFullCusProduct } from "@/internal/customers/add-product/createFullCusProduct.js";
 import { attachToInsertParams } from "@/internal/products/productUtils.js";
@@ -24,13 +27,11 @@ export const handleUpgradeSameInterval = async ({
   attachParams: AttachParams;
   config: AttachConfig;
 }) => {
-  const { curMainProduct: curCusProduct } = attachParamToCusProducts({
-    attachParams,
-  });
+  const curCusProduct = attachParamsToCurCusProduct({ attachParams });
 
   const stripeSubs = await getStripeSubs({
     stripeCli: attachParams.stripeCli,
-    subIds: curCusProduct!.subscription_ids || [],
+    subIds: curCusProduct?.subscription_ids || [],
     expand: ["items.data.price.tiers"],
   });
 
diff --git a/server/src/internal/invoices/previewItemUtils/getItemsForCurProduct.ts b/server/src/internal/invoices/previewItemUtils/getItemsForCurProduct.ts
index 565637e4e..3c0172396 100644
--- a/server/src/internal/invoices/previewItemUtils/getItemsForCurProduct.ts
+++ b/server/src/internal/invoices/previewItemUtils/getItemsForCurProduct.ts
@@ -53,7 +53,7 @@ export const getItemsForCurProduct = async ({
   const curPrices = cusProductToPrices({ cusProduct: curCusProduct });
 
   let items: PreviewLineItem[] = [];
-  let onTrial = isTrialing(curMainProduct!);
+  let onTrial = isTrialing(curCusProduct);
 
   for (const sub of stripeSubs) {
     for (const item of sub.items.data) {
diff --git a/server/tests/attach/addOn/addOn1.ts b/server/tests/attach/addOn/addOn1.ts
new file mode 100644
index 000000000..91b87b130
--- /dev/null
+++ b/server/tests/attach/addOn/addOn1.ts
@@ -0,0 +1,158 @@
+import { AutumnInt } from "@/external/autumn/autumnCli.js";
+import { initCustomer } from "@/utils/scriptUtils/initCustomer.js";
+import { APIVersion, AppEnv, Organization } from "@autumn/shared";
+import chalk from "chalk";
+import Stripe from "stripe";
+import { DrizzleCli } from "@/db/initDrizzle.js";
+import { setupBefore } from "tests/before.js";
+import { createProducts } from "tests/utils/productUtils.js";
+import { addPrefixToProducts, replaceItems } from "../utils.js";
+import {
+  constructProduct,
+  constructRawProduct,
+} from "@/utils/scriptUtils/createTestProducts.js";
+import {
+  constructArrearProratedItem,
+  constructFeatureItem,
+} from "@/utils/scriptUtils/constructItem.js";
+import { TestFeature } from "tests/setup/v2Features.js";
+import { attachAndExpectCorrect } from "tests/utils/expectUtils/expectAttach.js";
+import { expect } from "chai";
+import { expectProductAttached } from "tests/utils/expectUtils/expectProductAttached.js";
+
+export let pro = constructProduct({
+  items: [
+    constructFeatureItem({
+      featureId: TestFeature.Messages,
+      includedUsage: 100,
+    }),
+  ],
+  type: "pro",
+});
+
+export let addOn = constructRawProduct({
+  id: "add_on_1",
+  items: [
+    constructFeatureItem({
+      featureId: TestFeature.Messages,
+      includedUsage: 200,
+    }),
+  ],
+  isAddOn: true,
+});
+
+const testCase = "addOn1";
+
+describe(`${chalk.yellowBright(`${testCase}: Testing free add on, and updating free add on`)}`, () => {
+  let customerId = testCase;
+  let autumn: AutumnInt = new AutumnInt({ version: APIVersion.v1_4 });
+  let testClockId: string;
+  let db: DrizzleCli, org: Organization, env: AppEnv;
+  let stripeCli: Stripe;
+
+  let curUnix = new Date().getTime();
+
+  before(async function () {
+    await setupBefore(this);
+    const { autumnJs } = this;
+    db = this.db;
+    org = this.org;
+    env = this.env;
+
+    stripeCli = this.stripeCli;
+
+    addPrefixToProducts({
+      products: [pro, addOn],
+      prefix: testCase,
+    });
+
+    await createProducts({
+      autumn,
+      products: [pro, addOn],
+      customerId,
+      db,
+      orgId: org.id,
+      env,
+    });
+
+    const { testClockId: testClockId1 } = await initCustomer({
+      autumn: autumnJs,
+      customerId,
+      db,
+      org,
+      env,
+      attachPm: "success",
+    });
+
+    testClockId = testClockId1!;
+  });
+
+  it("should should attach pro product, then add on product", async function () {
+    await attachAndExpectCorrect({
+      autumn,
+      db,
+      org,
+      env,
+      stripeCli,
+      customerId,
+      product: pro,
+    });
+  });
+
+  it("should should attach add on product", async function () {
+    const preview = await autumn.attachPreview({
+      customer_id: customerId,
+      product_id: addOn.id,
+    });
+
+    await autumn.attach({
+      customer_id: customerId,
+      product_id: addOn.id,
+    });
+
+    const customer = await autumn.customers.get(customerId);
+
+    expect(customer.products.length).to.equal(2);
+    expectProductAttached({
+      customer,
+      product: addOn,
+    });
+    expectProductAttached({
+      customer,
+      product: pro,
+    });
+  });
+
+  const customItems = replaceItems({
+    items: pro.items,
+    featureId: TestFeature.Messages,
+    newItem: constructFeatureItem({
+      featureId: TestFeature.Messages,
+      includedUsage: 400,
+    }),
+  });
+
+  it("should update add on product", async function () {
+    const preview = await autumn.attachPreview({
+      customer_id: customerId,
+      product_id: addOn.id,
+      is_custom: true,
+      items: customItems,
+    });
+
+    await autumn.attach({
+      customer_id: customerId,
+      product_id: addOn.id,
+      is_custom: true,
+      items: customItems,
+    });
+
+    const customer = await autumn.customers.get(customerId);
+
+    expect(customer.products.length).to.equal(2);
+    expectProductAttached({
+      customer,
+      product: addOn,
+    });
+  });
+});