diff --git a/packages/better-auth/src/api/routes/sign-up.test.ts b/packages/better-auth/src/api/routes/sign-up.test.ts
index 09d856bbad..44f0a545ae 100644
--- a/packages/better-auth/src/api/routes/sign-up.test.ts
+++ b/packages/better-auth/src/api/routes/sign-up.test.ts
@@ -265,13 +265,14 @@ describe("sign-up user enumeration protection", async () => {
 		);
 	});
 
-	it("should call onExistingUserSignUp when autoSignIn is false", async () => {
+	it("should call onExistingUserSignUp when autoSignIn is false and requireEmailVerification is true", async () => {
 		const onExistingUserSignUp = vi.fn();
 		const { auth } = await getTestInstance(
 			{
 				emailAndPassword: {
 					enabled: true,
 					autoSignIn: false,
+					requireEmailVerification: true,
 					onExistingUserSignUp,
 				},
 			},
@@ -292,6 +293,33 @@ describe("sign-up user enumeration protection", async () => {
 		expect(onExistingUserSignUp).toHaveBeenCalledTimes(1);
 	});
 
+	it("should not call onExistingUserSignUp when autoSignIn is false without requireEmailVerification", async () => {
+		const onExistingUserSignUp = vi.fn();
+		const { auth } = await getTestInstance(
+			{
+				emailAndPassword: {
+					enabled: true,
+					autoSignIn: false,
+					onExistingUserSignUp,
+				},
+			},
+			{
+				disableTestUser: true,
+			},
+		);
+
+		const body = {
+			email: "callback-autosignin-no-verify@test.com",
+			password: "password123",
+			name: "Callback AutoSignIn No Verify",
+		};
+
+		await auth.api.signUpEmail({ body });
+		await expect(auth.api.signUpEmail({ body })).rejects.toThrow();
+
+		expect(onExistingUserSignUp).not.toHaveBeenCalled();
+	});
+
 	it("should not call onExistingUserSignUp when enumeration protection is inactive", async () => {
 		const onExistingUserSignUp = vi.fn();
 		const { auth } = await getTestInstance(
@@ -344,7 +372,7 @@ describe("sign-up user enumeration protection", async () => {
 		expect(onExistingUserSignUp).not.toHaveBeenCalled();
 	});
 
-	it("should return success for existing email when autoSignIn is disabled", async () => {
+	it("should throw for existing email when autoSignIn is disabled without requireEmailVerification", async () => {
 		const { auth } = await getTestInstance(
 			{
 				emailAndPassword: {
@@ -365,10 +393,32 @@ describe("sign-up user enumeration protection", async () => {
 
 		await auth.api.signUpEmail({ body });
 
-		const duplicatedSignUp = await auth.api.signUpEmail({ body });
+		await expect(auth.api.signUpEmail({ body })).rejects.toThrow();
+	});
 
-		expect(duplicatedSignUp.token).toBeNull();
-		expect(duplicatedSignUp.user.email).toBe(body.email);
+	it("should return token: null for new sign-up when autoSignIn is disabled", async () => {
+		const { auth } = await getTestInstance(
+			{
+				emailAndPassword: {
+					enabled: true,
+					autoSignIn: false,
+				},
+			},
+			{
+				disableTestUser: true,
+			},
+		);
+
+		const res = await auth.api.signUpEmail({
+			body: {
+				email: "new-auto-signin@test.com",
+				password: "password123",
+				name: "New User",
+			},
+		});
+
+		expect(res.token).toBeNull();
+		expect(res.user.email).toBe("new-auto-signin@test.com");
 	});
 });
 
diff --git a/packages/better-auth/src/api/routes/sign-up.ts b/packages/better-auth/src/api/routes/sign-up.ts
index 15f340edd9..5bf210714d 100644
--- a/packages/better-auth/src/api/routes/sign-up.ts
+++ b/packages/better-auth/src/api/routes/sign-up.ts
@@ -232,8 +232,10 @@ export const signUpEmail = <O extends BetterAuthOptions>() =>
 					);
 				}
 				const shouldReturnGenericDuplicateResponse =
-					ctx.context.options.emailAndPassword.autoSignIn === false ||
 					ctx.context.options.emailAndPassword.requireEmailVerification;
+				const shouldSkipAutoSignIn =
+					ctx.context.options.emailAndPassword.autoSignIn === false ||
+					shouldReturnGenericDuplicateResponse;
 				const additionalUserFields = parseUserInput(
 					ctx.context.options,
 					rest,
@@ -391,7 +393,7 @@ export const signUpEmail = <O extends BetterAuthOptions>() =>
 					}
 				}
 
-				if (shouldReturnGenericDuplicateResponse) {
+				if (shouldSkipAutoSignIn) {
 					return ctx.json({
 						token: null,
 						user: parseUserOutput(ctx.context.options, createdUser) as User<