Prefill Registration Data

Paylogic offers a feature to allow the prefilling of the personal data of a consumer during the sales process via a personalized URL. This can be used whenever a merchant already has the data of the consumers and wants to offer these consumers a more personalized and smooth ticketing process, or when a pre-registration step is used. The following sections describe the steps that third parties have to implement in order to provide the possibility of prefilling the registration form in the front office.

JSON data format

The first step is to construct the data. The data should be structured using JSON. The JSON data should adhere to the following format:

  "first_name": "Test Client First Name",
  "last_name": "Test Client Last Name",
  "email": "",
  "gender": "1",
  "birth_date": "1978-10-07",
  "phone_number": "0123456789",
  "address": "Address 1A",
  "postal_code": "9999AB",
  "city": "Groningen",
  "country": "NL"

The gender attribute should contain a code according to ISO 5218, which specifies the following codes:

  • 0 = not known
  • 1 = male
  • 2 = female
  • 9 = not applicable

The format of the birth_date attribute should be YYYY-MM-DD. This format is according to ISO 8601. Finally, the country code attribute should contain a value according to ISO 3166. For example, for The Netherlands the country code NL should be used. It should be mentioned that no certain format is required for postal_code, as long as its length is less than or equal to 12.

Compression and Encoding

The second step is to compress and encode the data. Compression helps to reduce the length of the data, as the URL should contain up to a maximum number of characters. It is not only that the JSON data itself might be long. Encoding also increases the length of the data by approximately 33%.

The pseudo code below illustrates the process of encoding and compression. It also includes the creation of the JSON data. The data should first be compressed and then encoded.

create the JSON data

create a string out of the JSON data

compress the data using gzip compatible compression

encode the data using base64 and make them url safe

The way encoding and compression can be implemented depends on which programming language is used. A simple implementation is illustrated both for Python and PHP. If there are any questions regarding the implementation, then please contact the Paylogic support team.


The compression is done using the zlib standard python module. The data is encoded to utf-8 prior to compression. Data encoding is performed using base64 as specified in RFC 3548

import json
import zlib

from base64 import urlsafe_b64encode

# construct the json data
json_data = {"first_name": "Test Client First Name", ... }

# create a string of the json data
json_data_string = json.dumps(json_data)

# encode the data to utf8 and compress it
compressed_data = zlib.compress(json_data_string.encode('utf8'))

# encode the data using base64 and urlsafe
encoded = urlsafe_b64encode(compressed_data)


The compression is done using the gzcompress method, which uses the zlib data format. The data is encoded to utf-8 prior to compression. Data encoding is performed using base64 as specified in RFC 3548

# create a string of the json data
$json_data_string = '{"first_name": "Test Client First Name", ... }';

# encode data to utf8 and compress it
$compressed_data = gzcompress(utf8_encode($json_data_string));

# encode the data using base64
$encoded_data = base64_encode($compressed_data);

# make data urlsafe
$encoded_data = str_replace(array('+','/'), array('-','_'), $encoded_data);

Transferring the data

The third step is to append the encoded and compressed data to the landing page URL. The landing page URL is the URL that is usually included within the invitation emails. The encoded and compressed data should be appended to the landing page URL after the fragment identifier (#). The advantage of this approach is that data after the fragment identifier is not sent over the network and is only used client-side.

The implementation of this is left to the third parties. The only constraint is that the appended data should have a specific form. We assume that the landing page URL contains some query parameters (substituted with '...' in the following example for clarity) and FGRAhdfhasAHDFA is the encoded and compressed data. Then, a landing page URL with the appended data would have the following form:

It is important to use pld as a parameter, as this is also used on the side of Paylogic, when retrieving the data from the URL. The above method will work if Paylogic handles the creation of the landing page.

Third party handles landing page

In case a third party handles the creation of the landing page, then one more step needs to be performed. The Javascript code below should be appended at the end of the landing page HTML document. This ensures that the data is read from the landing page URL and that it is appended in the queue URL, which resides as an iframe inside the landing page HTML document.

<script type="text/javascript">
var getHashParam = function() {
  window.location.hash.replace(/([^#&]+)/g, function(match) {
    // This is to ensure that if the variable contains '=' then they remain in the value.
    // for example: pld=FHadfsdhFJASDF3423==
    // In this case:
    //   key: pld
    //   value: FHadfsdhFJASDF3423==
    var param = match.split(/=(.+)?/);
    if (param[0] === "pld") {
        queue = document.getElementById('paylogic-frontoffice');
        queue.src = queue.src + '#' + param[0] + '=' + param[1];