I've had various fertility investigations at my clinic and they always invoice me before the appointment, or very soon after. A month ago I had some tests that they should have charged me £600 for, but they never sent me an invoice. I'm hoping I accidentally got that free because of an admin cockup and I don't really want to chase it but if I end up doing IVF later I don't want them to say hey you never paid for these tests and refuse to treat me because I don't pay for things?? Is that possible if they never even invoiced me?