diff --git a/packages/better-auth/src/api/routes/sign-up.test.ts b/packages/better-auth/src/api/routes/sign-up.test.ts
new file mode 100644
index 0000000000..37ccd61b13
--- /dev/null
+++ b/packages/better-auth/src/api/routes/sign-up.test.ts
@@ -0,0 +1,32 @@
+import { describe, expect } from "vitest";
+import { getTestInstance } from "../../test-utils/test-instance";
+
+describe("sign-up with custom fields", async (it) => {
+	it("should work with custom fields on account table", async () => {
+		const { auth, db } = await getTestInstance(
+			{
+				account: {
+					fields: {
+						providerId: "provider_id",
+						accountId: "account_id",
+					},
+				},
+			},
+			{
+				disableTestUser: true,
+			},
+		);
+		const res = await auth.api.signUpEmail({
+			body: {
+				email: "email@test.com",
+				password: "password",
+				name: "name",
+			},
+		});
+		expect(res.user).toBeDefined();
+		const accounts = await db.findMany({
+			model: "account",
+		});
+		expect(accounts).toHaveLength(1);
+	});
+});
diff --git a/packages/better-auth/src/api/routes/sign-up.ts b/packages/better-auth/src/api/routes/sign-up.ts
index a56b94dc76..2688bae6fd 100644
--- a/packages/better-auth/src/api/routes/sign-up.ts
+++ b/packages/better-auth/src/api/routes/sign-up.ts
@@ -134,7 +134,6 @@ export const signUpEmail = <O extends BetterAuthOptions>() =>
 				{
 					user: createdUser,
 					session,
-					error: null,
 				},
 				{
 					body: body.callbackURL
diff --git a/packages/better-auth/src/plugins/username/index.ts b/packages/better-auth/src/plugins/username/index.ts
index d9eb0eb934..d51fa228e4 100644
--- a/packages/better-auth/src/plugins/username/index.ts
+++ b/packages/better-auth/src/plugins/username/index.ts
@@ -122,15 +122,7 @@ export const username = () => {
 						...ctx,
 						_flag: "json",
 					});
-					if (res.error) {
-						return ctx.json(null, {
-							status: 400,
-							body: {
-								message: res.error,
-								status: 400,
-							},
-						});
-					}
+
 					const updated = await ctx.context.internalAdapter.updateUserByEmail(
 						res.user?.email,
 						{