EET does not require a receipt
The word receipt does not appear in the sales recording act. There is no duty to issue one, no fine for not doing so, and no receipt lottery. Almost everything written about a mandatory receipt describes the 2016 EET, which was a different system. You need not print the POK confirmation code on a receipt either.
01
You may still have to issue a document — under the VAT act
If you are registered for VAT, § 30a requires you to issue a simplified tax document, and § 29(1) gives the customer the right to demand a full one. That has nothing to do with sales recording and applies regardless of it.
Based on: zákon o DPH §30a, zákon o DPH §29 odst. 1
02
When you are not registered
Eetuj prints a proof of payment received. It is deliberately not called a tax document — passing yourself off as a DPH payer when you are not would not be honest.
03
How the receipt reaches the customer
Either you send it from your own e-mail app and your own address — and then we know nothing about it. Or we send it from doklad@eetuj.cz — and then the app shows you whether the e-mail arrived or bounced. The first way is more private, the second lets you track delivery. Without credit or a subscription you can send five receipts a month through doklad@eetuj.cz.