To open a FOP (Freedom of Payment) account in Poland for your son, he should be at least **13 years old**. However, it's essential to note that some banks may have different requirements or offer special accounts for minors, so it's best to check with the specific bank you're interested in. Additionally, as a parent or guardian, you may need to provide consent or be a co-signer on the account until your son reaches the age of majority, which is **18 years old** in Poland.

To open a FOP (Freedom of Payment) account in Poland for your son, he should be at least **13 years old**. However, it's essential to note that some banks may have different requirements or offer special accounts for minors, so it's best to check with the specific bank you're interested in. Additionally, as a parent or guardian, you may need to provide consent or be a co-signer on the account until your son reaches the age of majority, which is **18 years old** in Poland.

In the provided materials, there is not enough information to give an exact answer. However, in general, to open a sole proprietorship (Jednoosobowa działalność gospodarcza) in Poland, a person is required to have a PESEL number and a legal basis for staying in the country. Usually, this means that the person must be of legal age, i.e., have reached 18 years. If you have additional questions or want to learn more about the sole proprietorship registration process, let me know!

How can I confirm that I have a PESEL number in this case?

To confirm the presence of a PESEL number, you can use several methods: 1. **Document confirming receipt of PESEL**: Usually, this is a registration certificate that you receive after applying for a PESEL at the local authority. 2. **Request to the local authority**: You can contact the local authority (Urząd) and request information about your PESEL. This can be done in person or sometimes through online services. 3. **Check in the application**: If you have access to the mObywatel application, you can check your PESEL there. It is important to remember that the PESEL number is necessary for various administrative procedures, including opening a business in Poland. If you have additional questions or want to learn more about the process of obtaining a PESEL, let me know!

The Ukrainian tax number is not suitable, right?

Yes, you are right. The Ukrainian tax number is not suitable for opening a FOP in Poland. For this, a PESEL number (Powszechny Elektroniczny System Ewidencji Ludności) is required, which is a universal identification number in Poland. It is needed for work, taxes, medical care and other administrative procedures【12:0†source】. If you have any more questions or want to learn more about the process of obtaining a PESEL, let me know!