Yes, for most employers, part of the pay transparency rules apply regardless of the number of employees. The salary range in a job advertisement, the prohibition on asking about current salary, the requirement that job requirements are formulated in a gender-neutral manner, and the right of employees to request pay information: these are obligations without a threshold. One employee or two hundred, they generally apply to every employer once the national legislation transposing the directive has come into force.
What does depend on the size of your organization is the reporting obligation on the gender pay gap and the associated calculation module. That obligation applies from one hundred employees onwards, with a separate system for determining when you must report for the first time. Below that threshold, you are not required to report, but the basic obligations remain fully applicable. "Does this apply to me" is actually two questions: does it apply anyway, and does the reporting also apply. The answer to the first is yes for virtually every employer; the answer to the second depends on your workforce size.
No threshold for basic obligations
The four obligations without a minimum number of employees affect every employer that posts vacancies, conducts job interviews or has employees. An installation company with eight people on the payroll must include a salary range in the job advertisement just as much as an organization with hundreds of employees. The same applies to no longer asking a candidate about their current salary and to drawing up job requirements that do not indirectly point to one gender. The right of an employee to ask about the average pay level of comparable positions, broken down by gender, also has no lower limit. What exactly already applies and what is still awaiting transposition into national legislation varies per member state; this is different from the question of whether your company size plays a role. In the knowledge base per topic you will find the current status and the location in the official text for each obligation.
Where company size does make a difference
The reporting obligation on the gender pay gap, with the associated calculation per job category, is the obligation that only arises from one hundred employees onwards. Below that threshold, there is no obligation to provide figures, even though the salary range, the salary question prohibition, the gender-neutral criteria and the information right already apply. If your organization reaches the threshold of one hundred, then the question arises of how you classify employees into categories of equal pay for work of equal value and how you calculate the difference within those categories. This is a different question than whether the basic obligations apply to you, and deserves its own review moment when your workforce reaches that size.
Sector also plays a role
In addition to company size, the sector in which you operate sometimes also determines how the rules apply in detail. For semi-public employers, different emphases apply in some respects than for a regular private company, for example in how existing obligations relate to existing transparency requirements in that sector. This is an independent topic; what is relevant here is mainly that you answer the question "does this apply to me" not only on the basis of employee numbers, but also on the basis of the type of organization you are.
How to quickly check this for your own situation
Because the combination of company size, sector and the moment when national legislation in your country comes into force determines what exactly already applies, a general answer is always an approximation. The compliance check answers in a few questions what applies now, what will change in the short term and what only becomes relevant at reporting. This is done free of charge and without you needing to create an account, with always a reference to the underlying text so you can check it yourself.
If the basic obligations apply, what then
If the pay range, the ban on salary history inquiries, gender-neutral criteria, and the right to information apply to your organization, the next question is usually how you organize this structurally: a job classification that holds up, a remuneration policy that is documented, and a workflow for when an employee actually requests information. How such a system is structured and where the calculation module for employers with at least one hundred employees fits in, you can read on the page about how the system is structured. What remains free and what is part of a subscription is clearly set out on the pricing page.
This text describes how the obligations are structured and where the boundaries lie; it is not legal advice and not an assessment of your specific situation. If you are unsure whether, and at what point, an obligation applies to your organization, a lawyer or the competent supervisory authority remains the right place for a definitive answer. If you would first like an indication yourself, do the free quick-scan or browse through the knowledge base to see which part becomes relevant for you first.