AT&T Error 3 — What It Means & How to Fix It

What Does This Error Mean?

AT&T Error 3 is an authentication failure. When your gateway connects to AT&T's DSL network, it must log in using PPPoE credentials — a username and password tied to your account. Error 3 means that login was rejected. This is like typing the wrong password on a website — the door stays closed.

Affected Models

AT&T DSL customers
AT&T U-verse internet customers
AT&T BGW210 gateway
AT&T NVG589 gateway
AT&T NVG599 gateway
AT&T Pace 5268AC gateway

Common Causes

The PPPoE username or password stored in the gateway is incorrect or outdated
AT&T has reset or changed your account credentials after maintenance
Your AT&T account has been suspended for non-payment or a billing hold
The gateway firmware has corrupted the stored credentials
Your service type was changed (e.g., plan upgrade) and the line provisioning has not updated

How to Fix It

Restart your AT&T gateway. Unplug the power cord, wait 30 seconds, plug it back in. Wait 3 minutes for the connection attempt to complete and check if the broadband light turns green.

A temporary credential cache issue sometimes clears on its own after a reboot.
Check your AT&T billing status. Log into att.com and verify there are no unpaid bills or service holds on your account.

A suspended account will always fail PPPoE authentication until the billing issue is resolved.
If you manage your gateway's settings (advanced users): log into the gateway admin page, find the Broadband or DSL settings, and verify the PPPoE username. AT&T usernames are typically in the format: [10-digit-number]@att.com.

Do not change the password unless AT&T provides you with a new one.
Call AT&T and ask them to re-provision your line. Mention you are receiving an authentication failure (Error 3). They can push a re-provisioning command from their end.

Re-provisioning takes 2–5 minutes and often resolves Error 3 without any changes on your end.
If you recently changed your AT&T account password online, you may need to update the PPPoE password in your gateway. Call AT&T for the exact value — it may not be the same as your account portal password.

AT&T sometimes uses a separate PPPoE password that is different from your account login password.

When to Call a Professional

Error 3 almost always requires AT&T involvement. Call AT&T support at 800-288-2020 and explain that you are receiving Error 3 (PPPoE authentication failure). They can verify that your account is active, confirm the correct credentials, and re-provision your line if needed. Do not attempt to manually change PPPoE settings unless AT&T gives you specific values — incorrect settings will make it worse.

Frequently Asked Questions

Is AT&T Error 3 the same as Windows PPPoE Error 691?

They describe the same underlying problem — a failed PPPoE login. Error 691 is the Windows error code for an authentication failure on any PPPoE connection. AT&T Error 3 is displayed on AT&T gateways when their PPPoE login is rejected. The fix is the same: verify credentials, check billing status, and contact AT&T if needed.

I did not change anything, but Error 3 appeared this morning. Why?

AT&T sometimes performs overnight maintenance that can reset line provisioning. A credential mismatch can appear after a network configuration change on AT&T's side. Call AT&T and ask them to check whether your line provisioning is correct. This is a known issue and they can usually fix it quickly over the phone.

Can Error 3 be fixed without calling AT&T?

Sometimes a simple restart fixes a temporary authentication glitch. But if the error persists, it almost always requires AT&T to re-provision your line or correct your credentials on their system. There is no fix you can apply entirely on your own without AT&T's confirmation of correct PPPoE values.