Register to participate to a PTP

General conditions to participate

Taking part to ILC involves the acceptance of the general conditions for participation (see the general conditions for participating).

The test results of a same participation must be obtained “under conditions of repeatability” as defined in ISO 5725-1 (same operator, same test equipment, same environmental conditions, performance of all tests at the same time). The laboratories that registered for several participations to a same ILC must get their results “under conditions of reproducibility” as defined in ISO 5725-1 (different operators, different test equipments, different environmental conditions, performance of tests at different moments). However, for test for which several performances of testing are possible on a same sample (chemical analysis, metallography, physical characteristics of paint coatings, roughness), up to 8 determinations may be achieved in in between conditions. The statistical processing takes this particular issue into account.  Please consider this issue when deciding the number of your participations.


The prices for participation include:

  • A fee to participate to one ILC,
  • Transportation fees, for the ILC related to the weight of the samples and the location of sending the samples,
  • A discount, when the customer takes orders the participation to several ILC*.

* : A discount is given for participations of a same registration of several laboratories or/and of one laboratory to several ILC, as detailed in the price list.

The price list is available here: Price list

According to the European regulation concerning VAT, the customers established in the European Union (excepted France) are exempted to pay VAT if the are subjected to it in their own countries. If not, they have to pay the VAT at the French rate. The customers established outside of the European Union have not to pay any VAT.

Planning 2024

Please note that all the proficiency tests are not organized according the same schedule.

In order to know to which schedule the PT you are interested in belongs, we invite you to refer to the registration deadline of each PT (see Proficiency tests programs).




Longterm tests


Registration deadline






Date of shipment of samples




Deadline for carrying out the tests and providing the results




Date of delivery of reports




Note: After the deadline, registrations are only accepted within the limit of availability of samples.

In addition to the assessment of the bias and repeatability, the participation to ILC organised by CompaLab provides an individual estimate the uncertainties of your test results.

At last, for participants who need their results very quickly, some samples which properties are known through the results of former ILC are also available.


Registration process

Two registration modes are possible :

1 - Online registration, which is a totally on-line process, which can be achieved immediately in one step. Payment must then be made online with a credit card. A 20% discount is then applied, already taken into account in prices displayed on the CompaLab internet store (see the price list).

2 - Registration enabling payment by bank transfer, which allows the possibility of discount (see the price list).


Online registration process

For an online registration, please just select in the store the ILC to which you want to take part and the number of participations to each of them, then implement the registration process until payment. You get an acknowledgement of registration within 3 days of payment.

For a registration of several laboratories, please proceed separately for each laboratory.

Need more explanations ? contact us at or use the contact form.

Registration using payment by bank transfer

For registration using a payment by bank transfer, the process is made as follows:

  1. Registration by the customer with the registration form*;
  2. CompaLab verifies the information provided and sends the corresponding invoice to the customer;
  3. Payment of the invoice by the customer;
  4. Confirmation by CompaLab of the registrations, to the customer and to the participating laboratories;
  5. Each participant shall verify the information corresponding to him, especially the delivery address of the samples.

* : If the registration covers several laboratories and/or several ILC, the "customer" is the body that registrates the participants and pays the service.

To register in this way, please fill in the registration form and send it to CompaLab at

Need of more explanations ? contact us at or use the contact form.



For some programs, there is a risk that the number of registrations is insufficient with the normal procedure. To avoid this, a pre-registration procedure is put in place, as follows:

1 - Participants interested in participating pre-register using the registration form. No invoicing is made for this pre-registration;
2 - When at least 10 potential participants have pre-registered, CompaLab asks each of these pre-registrees to confirm their willingness to participate and what are the characteristics for which they commit to provide results;
3 - If at least 8 participants confirm their intention to participate, the CIL organisation concerned is engaged.

Those programs are listed at the end of the page "Proposed proficiency test programs". Pre-registration is possible using the registration form or online.