To facilitate senders to prepare their system, samples of the Do-not-call Registers are made available here.  Even though these samples do not contain real data and cannot reflect the size of the actual registers, they serve to illustrate the format of the files, and can be used to test the file integrity checking procedure.

1. Download Sample Do-not-call Registers

The Do-not-call Registers are available for downloading in compressed zip format. A sender might choose to download Do-not-call Registers containing numbers only or Do-not-call Registers containing both numbers and registration dates.  A sample file for each of them is provided here:

After decompressing the zip file, the original format is in plain text format containing one telephone number (normally an 8-digit number in a row) per line or a telephone number and a date code separated by a comma per line.

2. Download Sample SHA256 Checksum file

In order to make sure your downloaded Do-not-call Register is not corrupted, a 'checksum' file is available alongside the respective Do-not-call Register. The checksum file contains a 'SHA256' checksum value of the zip file. A sample SHA256 file corresponding to the above Do-not-call register is provided here:

3. How to check file integrity

You can verify the integrity of the downloaded file against the checksum value stored in the checksum file. This is an important step to ensure that the downloaded Do-not-call Register is not corrupted due to transmission over the Internet. Please follow the steps below to check and compare the checksum values.

  1. Copy the downloaded DNC register file and its SHA256 checksum file into a folder (e.g. C:\dnc).
  2. Start a Command Prompt by pressing the Windows key and R key simultaneously to launch the Run window, then type “cmd” and click OK button in the Run window.

    The Command Prompt window will be displayed

  3. Change directory (command: cd) to the folder where the downloaded file resides. (e.g. C:\dnc)
  4. Get the checksum value of the DNC register file (command: certutil) and display the checksum value stored in the SHA256 checksum file (command: type).

    > certutil -hashfile [filename of DNC register file] SHA256

    > type [filename of SHA256 checksum file]

    If the integrity of the DNC register file is conserved, the checksum values should be the same as shown below.