Letter ID
Process and track letters easily

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 Letter ID is is a dynamic, postal data matrix code used to uniquely identify consignments, or as a supplement to franking on the letter.

  • Shipment-based address verification for preventing returns 
  • Individualization of Letter ID content, such as customer- and/or shipment number 
  • Verification of completeness of printing or identification of letter content 
  • Track the sorting of consignments both on the outward and return journeys
  • Digitized, automated processing of returns

Who is this service for?

Letter ID is a service for business customers who maintain a billing relationship with Swiss Post.

Service providers from the printing industry make their range of offers stand apart from the competition using Letter ID and support their customers in optimizing processes and making cost savings.


Movers’ addresses
Use of movers’ addresses for “Shipment-based address verification”


1.25 CHF/addresse

Digitization of returns
Digitization of returns or receipt of digital returns information


0.09 CHF/returns

Qualified disposal
“Qualified disposal” or shredding or returns including their sensitive content


0.02 CHF / returns

All prices in CHF
Prices for returns including VAT 
Prices per movers’ addresses excl. VAT

Here’s how it works


Label your letter consignments with a postage paid impression and the data matrix code letter ID. Keep to the specifications in the “Barcodes and data matrix codes for letter mail” manual when preparing your data matrix code and creating the consignments. 


We will first check how the data matrix code has been prepared and positioned to ensure we can machine-process your consignments. You will receive a final proof after homologation. 


Use the PP franking for bulk mailings and create a dispatch list/delivery note for letter posting. Select the “PP franking with Letter ID” mailing option and enter the order number included in the data matrix code.

Drop off your PP-franked consignments together with the dispatch list/delivery note at your nearest branch or one of our letter and logistics centers. You can also have your consignments collected by Swiss Post.


Track consignments on the outward and return journey.

Track letters using Letter ID

You can track the sorting results of your Letter ID consignments using the Swiss Post Customer Login for the “Track consignments” online service -> “Advanced search” -> “Letters with Letter ID”. You can also set up active notification via e-mail.


Do you want to receive your data automatically each day? Set up the electronic “DataTransfer” interface. 

Find out more


Letter ID (dynamic code, type 21/20)

Letter ID light (previously PP Easy; static code, type 31) 

Uniqueness − each consignment has an individual data matrix code.

Ambiguity − all consignments have the same data matrix code with the same content

The production process should ideally use software since each consignment has its own code.  Possibility of producing smaller volumes (10,000 addresses per dispatch) within the“Create postage paid impressions” online service

The data matrix only needs to be created once and is therefore easy to implement.  It’s easy to do via the “Create postage paid impressions” online service.

Shipment-based address verification is possible thanks to the individual character of the code.

Shipment-based address verification not possible.

Alphanumeric digits may be used freely in the code by the customer.

No digits may be freely used by the customer.

Individual information on sorting consignments.

No individual information; information at order level only. 

Individual information on returns and automated further processing possible.  

No individual information except if the individual images of the return shipments are viewed. In this case, an individual conclusion can also be drawn. 

An interface with Swiss Post via “DataTransfer” is required to use “shipment-based address verification” with Letter ID. Certain specifications also need to be implemented. 

You can choose from the following options: 

  • Digitization
  • Disposal (simple and/or qualified) 
  • Redirect mail 

You can create the data matrix codes for Letter ID and Letter ID light in the “Create postage paid impressions” online service. 

To create the dynamic Letter ID you need to import your recipient addresses. The maximum number of data matrix codes created for each generation process totals 10,000.  

When creating the static Letter ID light, you generate a single data matrix code for use with varying letter volumes.  

Send a data matrix code along with the letter layout to one of our “Final proof” Competence Centers in your region.

Verification is free and you will receive a written response within 72 hours. 

With the dynamic Letter ID, it is beneficial if you submit five copies for homologation to enable the dynamic filling-in process to be simulated. This is not necessary with Letter ID light since the filling-in process is always the same.

To post PP-franked consignments using Letter ID or Letter ID light, you use a dispatch list, which is simply a delivery note. 

For consignments using Letter ID light, simply enter “postage paid impression” as the “Dispatch type”. For consignments using Letter ID, by contrast, record the consignments using “postage paid impression with Letter ID” as the dispatch type and enter the order number integrated into the data matrix code Letter ID.

We would be pleased to provide you with personalized advice!
Do you have any questions about Letter ID? Request a personal meeting to find out more about your options.

Give us a call

Monday to Friday: 7.30 a.m. – 6 p.m. Saturday 8 a.m. – 12 noon

CHF 0.08/min. from landline phones within Switzerland

0848 888 678
0848 888 678

Write to us

Send your query directly online to our specialists.

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Our address

Post CH Ltd
Swiss Post Contact Center
Wankdorfallee 4
3030 Bern