Audi Radio Code (AUZ)

After a flat battery or battery replacement, Audi factory radios display SAFE or CODE and require a four-digit unlock code before they will operate. The code is generated from the unit's unique serial number, which on Audi radios is known as the AUZ serial — though some older units use a SEZ or BP prefix instead. This guide covers every Audi audio generation from the Concert and Symphony through to MMI 3G+ units.

Understanding the AUZ Serial Number

Audi's radio serial numbering has evolved across generations. Most Concert and Symphony units from 2000 onwards carry a 14-character serial beginning with AUZ (e.g. AUZ2Z2B1234567). Earlier units — particularly those built by Philips — may carry a SEZ prefix. Blaupunkt-built units may show a BP serial. In all cases the full serial is what you need; the prefix tells the lookup system which algorithm to apply.

How to Display the Serial Number on Screen

Most Audi Concert and Symphony radios support an on-screen serial display without needing to remove the unit:

Audi Concert (B6/B7/B8 era)

Press and hold the AM and SCAN buttons simultaneously.
The serial number will appear across the display. Note all characters carefully — some scroll in two halves.

Audi Symphony / RNS-E Navigation

Press and hold FM and RDS (or TP) simultaneously.
The serial scrolls across the screen.

Audi MMI 3G / 3G+

MMI-equipped vehicles (A4 B8, A6 C7, A8, Q5, Q7 from approximately 2008) handle security differently. The MMI system may display the serial in the Settings > System > Version information menu. If the unit requires a PIN after battery disconnection, the MMI controller is used to enter it.

If the on-screen method is unavailable, remove the unit using DIN extraction keys and read the AUZ serial from the label on the casing. Once you have it, MyRenaultRadioCode.com will retrieve your code instantly.

Entering the Code on an Audi Radio

For Concert and Symphony units:

With CODE 1_ _ _ on screen, press button 1 to cycle the first digit.
Press button 2 for the second digit, 3 for the third, 4 for the fourth.
Press and hold the AM or mode button to confirm. The radio will unlock and resume normal operation.

Common Audi Radio Models and Serials

Radio model	Audi models / years	Serial prefix	OEM
Classic / Concert (early)	A3 8L, A4 B5/B6, A6 C5 — 1996–2005	SEZ / BP	Philips / Blaupunkt
Concert (3rd gen)	A3 8P, A4 B7 — 2003–2008	AUZ	Harman / Philips
Symphony	A4 B6/B7, A6 C6 — 2001–2008	AUZ	Harman
RNS-E Navigation	A3 8P, A4 B7, TT — 2003–2010	AUZ	Harman
MMI 2G / 3G	A4 B8, A6 C7, Q5 — 2008–2018	AUZ / SEZ	Harman
MMI 3G+	A4 B9, A6 C8, A8 D5 — 2015–2022	AUZ	Harman

Popular Audi Models Requiring Radio Codes

The following generations are among the most common Audi vehicles presented for radio code retrieval:

A3 8P / 8V (2003–2020) — Concert or MMI depending on trim
A4 B7 / B8 (2004–2015) — Symphony, Concert or MMI
A6 C7 (2011–2018) — MMI 3G+
A1 8X (2010–2018) — Concert
Q5 8R (2008–2017) — MMI 3G

Troubleshooting

SAFE persists for over an hour: Ensure the ignition has been left on continuously. Switching off resets the countdown on some units.
Incorrect code entered: Audi units impose a temporary lockout — leave power on and wait for the prompt to return before retrying.
MMI requests a different PIN: The MMI transport lock (activated in new-car delivery mode) is separate from the radio code; check the owners manual for the default PIN.

Frequently Asked Questions

Is the AUZ serial the same across all VAG brands?

No. Volkswagen Group radios use different serial prefixes per brand: Volkswagen uses VWZ, Audi uses AUZ (or SEZ on older units), SEAT uses SWZ and Skoda uses SKZ. The lookup algorithm also varies, so it is important to select the correct brand on any retrieval service.

My Audi RNS-E shows a different code format — is it still AUZ?

Yes. The RNS-E navigation unit uses the same 14-character AUZ serial and standard four-digit code system. The serial can be displayed via the built-in service menu or read from the unit label.

Do all Audi MMI units need a radio code?

Older MMI 2G and 3G units use the standard code system. Newer MIB-based units in post-2016 Audis may use component protection, which requires dealer authorisation rather than a simple code entry. Check which generation your vehicle has before ordering.

Can I find my code without removing the unit from an A4 B8?

Yes, in most cases. The A4 B8 Concert unit supports the hold AM+SCAN on-screen display method described above. Visit MyRenaultRadioCode.com with the displayed serial to retrieve the code.