I’m working on a small SAAS project and want to add subscription payments. I’m based in Poland, so Stripe is not an option. Also, I don’t have registered company.
Any advice on the good service that can solve this problem for me?
Paymentwall.com or paddle
If you did have a company, I would recommend Paddle as well. I've been using it on https://tookapic.com for several years now. They make taxes much easier.
In many EU countries you do not need to open a company under a certain amount of money/ year. Sure that in Poland is not the same? what about Braintree ? https://www.braintreepayments.com/at/country-selection
Paddle? They'll deal with EU VAT for you and EU VAT is a big problem you want to avoid when you're starting.
I don't know about Poland but in the UK you don't need to register a company to sell so I'd confirm you really need to do this.