Registered Mail Code 673: Who Sends It and What to Do Immediately

Published on Dec 01, 2025
Updated on Dec 01, 2025
reading time

Collection notice for a registered letter with the barcode and identification number 673 in the foreground.

Finding a collection notice in your mailbox can cause some apprehension. The inability to immediately know the sender and the content of the communication fuels doubts and worries. However, thanks to the codes on the notice, it’s possible to get a clear idea of its origin. In this comprehensive guide, we will analyze the meaning of registered mail code 673, identifying the most likely senders and providing practical guidance on how to act. We will explore a system that, while rooted in bureaucratic tradition, is now facing digital innovation.

The registered mail system in Italy is based on a numerical code that allows for the classification of the communication’s nature even before it is collected. The first few digits of the barcode on the collection notice are a crucial clue. Understanding this mechanism is the first step to deciphering the message and managing the situation with awareness, avoiding the anxiety that often accompanies the wait.

Advertisement

Decoding the Collection Notice: The Role of the Registered Mail Code

When the mail carrier finds no one home to deliver a registered letter, they leave a “collection notice” (avviso di giacenza). This white or green slip contains essential information: the post office where the envelope can be collected and, most importantly, a barcode. The first two or three digits of this code are the key to an initial identification. Although they cannot reveal the exact content, they significantly narrow down the field of possible senders. For example, different codes can indicate communications from INPS (the Italian National Social Security Institute), banking institutions, or, as in the case of 673, tax authorities. This system, well-established in Italian administrative culture, represents a bridge between traditional paper communication and the need for rapid identification in the digital age.

Discover more →

Registered Mail Code 673: The Most Common Senders

Registered mail code 673 is almost always associated with communications from the Agenzia delle Entrate-Riscossione (the agency that replaced Equitalia) or the Agenzia delle Entrate (the Italian Revenue Agency). Therefore, receiving a notice with this code indicates, with high probability, a tax-related notification. It could be a demand for payment of unpaid taxes, such as IRPEF (personal income tax), IVA (VAT), or local taxes like IMU (property tax) or TARI (waste tax). Other codes, such as 670, 671, and 689, are also often linked to tax bills, creating a family of “tax” codes that citizens learn to recognize. The specificity of these codes is an example of how the public administration attempts to organize and standardize its official communications.

Read also →

What a Registered Letter with Code 673 Contains

Advertisement

A registered letter identified by code 673 typically contains an official communication of a fiscal nature. In most cases, it is a tax bill (cartella di pagamento), which is a formal request for the payment of unpaid taxes, duties, or penalties. However, this is not the only possibility. The envelope could also contain a request for additional documentation for a tax audit, an assessment notice, or communications regarding tax refunds. In some rarer cases, it might concern the non-payment of car tax or a fee to a land reclamation consortium. It is important to note that, although often associated with payment requests, the content is not always negative.

Discover more →

How to Act Upon Receipt: A Practical Guide

Upon receiving a collection notice with code 673, the first rule is do not ignore it. The letter will be held at the post office for 30 days; after this period, it will be returned to the sender, and the notification will be considered legally completed through “compiuta giacenza” (notification by completed holding period), with all the legal consequences that entails. It is therefore essential to go to the indicated post office with a valid ID to collect the communication. Once the envelope is opened, it is crucial to read its contents carefully, paying close attention to the deadlines for payment or for a possible appeal. If the content seems complex or you have doubts about the legitimacy of the request, it is advisable to consult a professional, such as an accountant or a tax lawyer.

Tradition and Innovation in Institutional Communication

The registered mail system, with its numerical codes, represents an established tradition in the Italian and Mediterranean bureaucratic landscape, where paper communication with legal value has always played a central role. However, this system is evolving. Innovation is manifested through integration with digital tools. The ability to track the shipment online via the Poste Italiane website is a first step. Furthermore, the introduction of the digital domicile (PEC – Certified Electronic Mail) for professionals and businesses is shifting a significant portion of official communications from paper to digital. Despite this, physical registered mail, especially for individuals, remains an indispensable tool to ensure the certainty of notification, representing a bridge between the solidity of tradition and the needs of an administration that is moving, albeit slowly, towards modernization.

In Brief (TL;DR)

Registered mail code 673 often signals a tax collection notice: here is a practical guide to recognize the sender and understand how to proceed.

This code, often associated with a payment notice, identifies a communication sent by the Agenzia delle Entrate-Riscossione (formerly Equitalia) or other collection agencies.

In this article, you will discover how to definitively identify the sender of a registered letter with code 673, which is often the Agenzia delle Entrate-Riscossione, and what the correct steps are to follow upon collection.

Advertisement

Conclusion

disegno di un ragazzo seduto a gambe incrociate con un laptop sulle gambe che trae le conclusioni di tutto quello che si è scritto finora

Registered mail code 673, while understandably causing concern, is an element of clarity in a complex system. It identifies, with a high degree of accuracy, a communication from the tax authorities, almost always from the Agenzia delle Entrate or the Agenzia delle Entrate-Riscossione. The most important action to take is to collect the letter without delay to understand the nature of the communication and meet the deadlines. Ignoring the notice does not solve the problem but can worsen it. Facing the situation promptly, by getting informed and, if necessary, seeking qualified support, is the best way to effectively manage any type of notification, turning a moment of anxiety into a conscious and decisive action. In a world that balances tradition and innovation, paper-based registered mail remains a cornerstone of legal communication, but knowledge of its codes, like registered mail code 785 or registered mail code 666, gives citizens an extra tool to navigate the system.

Frequently Asked Questions

disegno di un ragazzo seduto con nuvolette di testo con dentro la parola FAQ
What does it mean to receive a registered letter with code 673?

Receiving a registered letter with code 673 indicates, in most cases, a communication from the Agenzia delle Entrate (Italian Revenue Agency) or the Agenzia delle Entrate-Riscossione (the collection agency, formerly Equitalia). It could be a tax bill, an assessment notice, a request for documents, or another tax-related communication.

Is the sender of a 673 registered letter always the tax agency?

Although it is strongly associated with tax communications, it is not an absolute rule. The Agenzia delle Entrate-Riscossione is the most frequent sender for this code. However, in rare cases, there could be other senders, but it is standard practice for this code to identify collection-related documents.

How can I get an idea of the sender before collecting the letter?

The collection notice left by the mail carrier is the first clue. The first digits of the barcode (in this case, 673) identify the type of communication. Even if the sender’s name is not specified on the notice, the code itself is a strong indicator. However, to be absolutely certain, you must go to the post office and collect the document.

What should I do when I receive a collection notice with code 673?

It is essential to go to the post office indicated on the notice to collect the registered letter as soon as possible. Ignoring the communication is not a solution, as the document will still produce its legal effects once the holding period has passed.

What are the consequences if I don’t collect a registered letter with code 673?

Failure to collect does not stop the legal process. The registered letter is considered served by “compiuta giacenza” (notification by completed holding period) after being held at the post office for 30 days, after which it is returned to the sender. This means that, by law, the communication has occurred, and the deadlines for payments or any appeals will begin to run, even if you have not physically collected the document.

Francesco Zinghinì

Electronic Engineer expert in Fintech systems. Founder of MutuiperlaCasa.com and developer of CRM systems for credit management. On TuttoSemplice, he applies his technical experience to analyze financial markets, mortgages, and insurance, helping users find optimal solutions with mathematical transparency.

Did you find this article helpful? Is there another topic you'd like to see me cover?
Write it in the comments below! I take inspiration directly from your suggestions.

Leave a comment

I campi contrassegnati con * sono obbligatori. Email e sito web sono facoltativi per proteggere la tua privacy.







No comments yet. Be the first to comment!

No comments yet. Be the first to comment!

Icona WhatsApp

Subscribe to our WhatsApp channel!

Get real-time updates on Guides, Reports and Offers

Click here to subscribe

Icona Telegram

Subscribe to our Telegram channel!

Get real-time updates on Guides, Reports and Offers

Click here to subscribe

Condividi articolo
1,0x
Table of Contents