Never use the term employer (unless you really are a salaried employee)
State that you are visiting a client of your consulting business.
update (because of negative comments) It is highly unlikely you actually have an employer-employee relationship in the same terms as viewed by the IRS. However, especially for people for whom English is not their primary language, it is common to refer to my boss or my employer in conversation.
In the formal context of answering visas, use the simplest and least-likely-to-be-misinterpreted answer.
Similarly when talking to immigration officials - be very careful of your precise words because they have some trigger phrases.
You do not have to have a formal local corporation to be an independent business with a client in the USA. Different jurisdictions have entirely different legal interpretations - be very aware of yours and any areas which are loosely defined.
I have worked remotely for many US clients. At different times I have had different local Australian corporate structures. I have often only ever had the one regular client with a person I regarded as my boss but was always clear that they are legally not an employer.
Good luck getting things organised before the next US government shutdown!