you can create a user like this

        RegisterModel regModel = RegisterModel.CreateModel();
        regModel.Username = model.siemail;
        regModel.Email = model.siemail;
        regModel.Password = model.sipassword;
        regModel.Name = model.firstName + " " + model.lastName;

        MembershipCreateStatus regStatus = new MembershipCreateStatus();

        MembershipUser user = Members.RegisterMember(regModel, out regStatus, false);
        if (regStatus != MembershipCreateStatus.Success)
        {
            throw new System.Exception("Unable to register user: " + regStatus);
        }

Thank you. I might have approached this wrong. I just went to the docs that describes how to create user using userservice. That works too.

My problem is that I can't find how to send the invite - your approach doesn't allow this either. Correct ?

at what stage do you want to send an invite? Do you want the invite to have some sort of validation link. If you could explain the flow that you require I can explain what you need to do.

Our registration process involves an email confirmation step so it is quite straight forward to do.

Consider the flow in Umbraco UI where you in the usersection can either invite or create a user.

I thought that the invite user feature was available via Api (send invitation and accept invitation)

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