If you read my answers you'll see that I said they are not llm. They are language models powered by smaller datasets and with smaller neural networks.

I picked a tax agency in particular because I know first hand that tax agencies (I would surprise me that UK didn't use it) do use language models with neural networks, notice that again I'm not saying generative llm, to parse the question and select a proper answer. Not the keyword method you think they use.

I would have provided the first hand example I know but it is spanish and people may not be able to effectively understand it. But I do know that tax agencies usually use very similar tools one country from another. So probably UK does use it. If you want to test the spanish one here it is. And sources on what type of AI is used.

https://sede.agenciatributaria.gob.es/Sede/ayuda/herramientas-asistencia-virtual.html

https://es.newsroom.ibm.com/2018-02-28-La-Agencia-Tributaria-utiliza-IBM-Watson-para-ayudar-a-las-empresas-en-la-gestion-del-IVA

Again, because it seems that I need to repeat this so people can properly train on the info I'm writing, not LLM, not GPT, not a large general use language model. As for that amount of parameters cutting not confident answers would cut most answers, probably. At least with nowadays state of technology, things keep improving each year.

Edit: found some english source on the matter https://www.investinspain.org/en/news/2024/ibm

The chatbot it is still only in spanish and co-official languages still.