diff --git a/e2e/vendors/vendors.spec.ts b/e2e/vendors/vendors.spec.ts
index e8f54bef..bf98e8c5 100644
--- a/e2e/vendors/vendors.spec.ts
+++ b/e2e/vendors/vendors.spec.ts
@@ -409,7 +409,16 @@ test.describe("Vendor directory prototype parity", () => {
     );
     expect((await page.locator("tbody tr").first().boundingBox())?.height).toBe(52);
     await expect(page.getByText("Gateway Plumbing")).toBeVisible();
-    await expect(page.getByText("+1")).toBeVisible();
+    const tradeBadge = page.getByTestId("vendor-trade-badge").first();
+    await expect(tradeBadge).toHaveText("+1");
+    await tradeBadge.hover();
+    await expect(page.getByRole("tooltip")).toHaveText("Backflow Preventers");
+    await tradeBadge.focus();
+    await expect(tradeBadge).toBeFocused();
+    await tradeBadge.click();
+    await expect(page.getByRole("dialog")).toHaveCount(0);
+    await tradeBadge.press("Enter");
+    await expect(page.getByRole("dialog")).toHaveCount(0);
     await expect(page.getByText("2 active technicians")).toBeVisible();
     await expect(page.getByText("2 active · 1 inactive")).toBeVisible();
     await captureVisual(page, "/tmp/seahaven-vendor-implemented-list.png");
diff --git a/src/app/(protected)/vendors/_components/vendors-table.tsx b/src/app/(protected)/vendors/_components/vendors-table.tsx
index e2651e39..de239409 100644
--- a/src/app/(protected)/vendors/_components/vendors-table.tsx
+++ b/src/app/(protected)/vendors/_components/vendors-table.tsx
@@ -51,6 +51,12 @@ function stopPropagation(event: MouseEvent): void {
   event.stopPropagation();
 }
 
+function stopTradeBadgeKeyDown(event: KeyboardEvent): void {
+  if (event.key !== "Enter" && event.key !== " ") return;
+  event.preventDefault();
+  event.stopPropagation();
+}
+
 interface TruncatedTextProps {
   value: string;
   testId: string;
@@ -132,7 +138,8 @@ interface VendorTableRowProps {
 function VendorTableRow({ row, onOpenDetail, onOpenEdit }: VendorTableRowProps) {
   const trades = splitTrades(row.tradeSpecialties);
   const primaryTrade = trades[0] ?? "—";
-  const extraTrades = trades.length > 1 ? trades.length - 1 : 0;
+  const omittedTrades = trades.slice(1);
+  const extraTrades = omittedTrades.length;
   const { locationText, phoneText } = getVendorDisplayValues(row);
   const rowKey = String(row.id ?? `company-${row.companyId ?? ""}`);
 
@@ -204,19 +211,27 @@ function VendorTableRow({ row, onOpenDetail, onOpenEdit }: VendorTableRowProps)
           <Stack direction="row" spacing={0.5} sx={{ alignItems: "center" }}>
             <span>{primaryTrade}</span>
             {extraTrades > 0 && (
-              <Box
-                component="span"
-                sx={{
-                  borderRadius: "9999px",
-                  backgroundColor: "var(--color-bg-muted)",
-                  px: 0.75,
-                  py: 0.25,
-                  fontSize: 10.5,
-                  lineHeight: 1.2,
-                }}
-              >
-                +{extraTrades}
-              </Box>
+              <Tooltip title={omittedTrades.join(", ")} placement="top" arrow>
+                <Box
+                  component="span"
+                  tabIndex={0}
+                  aria-label={`+${extraTrades} more ${extraTrades === 1 ? "trade" : "trades"}: ${omittedTrades.join(", ")}`}
+                  data-testid="vendor-trade-badge"
+                  className="focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-1 focus-visible:outline-[var(--color-primary)]"
+                  onClick={stopPropagation}
+                  onKeyDown={stopTradeBadgeKeyDown}
+                  sx={{
+                    borderRadius: "9999px",
+                    backgroundColor: "var(--color-bg-muted)",
+                    px: 0.75,
+                    py: 0.25,
+                    fontSize: 10.5,
+                    lineHeight: 1.2,
+                  }}
+                >
+                  +{extraTrades}
+                </Box>
+              </Tooltip>
             )}
           </Stack>
         )}
diff --git a/src/test/app/(protected)/vendors/vendors-list.test.tsx b/src/test/app/(protected)/vendors/vendors-list.test.tsx
index b3572218..dd0070b8 100644
--- a/src/test/app/(protected)/vendors/vendors-list.test.tsx
+++ b/src/test/app/(protected)/vendors/vendors-list.test.tsx
@@ -244,6 +244,99 @@ describe("VendorsListPage", () => {
     );
   });
 
+  it("shows omitted trade names on the +N badge tooltip on hover and keyboard focus", async () => {
+    setupDefaults();
+    const multiTradeVendor: VendorListItem = {
+      ...activeVendor,
+      tradeSpecialties: "Backflow Preventers, Water Heaters, Drain Cleaning",
+    };
+    useVendorsList.mockImplementation((params: { isActive?: boolean; pageSize?: number }) => {
+      if (params.pageSize === 1) return result([], 1);
+      return params.isActive ? result([multiTradeVendor], 1) : result([], 0);
+    });
+
+    renderWithProviders(<VendorsListPage />, { route: "/vendors", withAuth: false });
+
+    const badge = screen.getByTestId("vendor-trade-badge");
+    expect(badge).toHaveTextContent("+2");
+    expect(screen.getByText("Backflow Preventers")).toBeInTheDocument();
+    expect(badge).toHaveAttribute("aria-label", "+2 more trades: Water Heaters, Drain Cleaning");
+
+    await userEvent.hover(badge);
+    const tooltip = await screen.findByRole("tooltip");
+    expect(tooltip).toHaveTextContent("Water Heaters, Drain Cleaning");
+    expect(tooltip).not.toHaveTextContent(/Backflow/);
+    await userEvent.unhover(badge);
+    await waitFor(() => expect(screen.queryByRole("tooltip")).not.toBeInTheDocument());
+
+    fireEvent.keyDown(document, { key: "Tab" });
+    badge.focus();
+    expect(badge).toHaveFocus();
+    expect(await screen.findByRole("tooltip")).toHaveTextContent("Water Heaters, Drain Cleaning");
+  });
+
+  it("does not show the +N badge when the vendor has a single trade", () => {
+    setupDefaults();
+    useVendorsList.mockImplementation((params: { isActive?: boolean; pageSize?: number }) => {
+      if (params.pageSize === 1) return result([], 1);
+      return params.isActive ? result([activeVendor], 1) : result([], 0);
+    });
+
+    renderWithProviders(<VendorsListPage />, { route: "/vendors", withAuth: false });
+
+    expect(screen.queryByTestId("vendor-trade-badge")).not.toBeInTheDocument();
+    expect(screen.getByText("Backflow Preventers")).toBeInTheDocument();
+  });
+
+  it("does not open the vendor detail when the +N badge is clicked or activated by keyboard", async () => {
+    setupDefaults();
+    useVendorCompanyRoster.mockReturnValue({
+      data: activeRoster,
+      isLoading: false,
+      isError: false,
+      error: null,
+      refetch: vi.fn(),
+    });
+    const multiTradeVendor: VendorListItem = {
+      ...activeVendor,
+      tradeSpecialties: "Backflow Preventers, Water Heaters, Drain Cleaning",
+    };
+    useVendorsList.mockImplementation((params: { isActive?: boolean; pageSize?: number }) => {
+      if (params.pageSize === 1) return result([], 1);
+      return params.isActive ? result([multiTradeVendor], 1) : result([], 0);
+    });
+
+    renderWithProviders(<VendorsListPage />, { route: "/vendors", withAuth: false });
+
+    const badge = screen.getByTestId("vendor-trade-badge");
+
+    await userEvent.click(badge);
+    expect(screen.queryByRole("heading", { level: 2, name: "Adam Whyte" })).not.toBeInTheDocument();
+
+    badge.focus();
+    await userEvent.keyboard("{Enter}");
+    await userEvent.keyboard("{Space}");
+    expect(screen.queryByRole("heading", { level: 2, name: "Adam Whyte" })).not.toBeInTheDocument();
+  });
+
+  it("relies on the MUI tooltip instead of a native title attribute on the +N badge", () => {
+    setupDefaults();
+    const multiTradeVendor: VendorListItem = {
+      ...activeVendor,
+      tradeSpecialties: "Backflow Preventers, Water Heaters",
+    };
+    useVendorsList.mockImplementation((params: { isActive?: boolean; pageSize?: number }) => {
+      if (params.pageSize === 1) return result([], 1);
+      return params.isActive ? result([multiTradeVendor], 1) : result([], 0);
+    });
+
+    renderWithProviders(<VendorsListPage />, { route: "/vendors", withAuth: false });
+
+    const badge = screen.getByTestId("vendor-trade-badge");
+    expect(badge).not.toHaveAttribute("title");
+    expect(badge).toHaveAttribute("tabIndex", "0");
+  });
+
   it("reports the filtered totalCount in the footer when page rows are fewer than total", () => {
     setupDefaults();
     const pageVendors = Array.from({ length: 3 }, (_, index) => ({