Do I need a visa to visit and consult in the UK

Hello Top Consultant Community. I have a question about whether I need a visa.

I am an American. My residence is in USA. I am a computer specialist in a narrow field with contracts around the world. In the UK, a larger consulting company has been sub-contracting me to work. This year, I have been flying into the UK almost once a month for a week or two. The reason for the trips are to advise either the consulting company or their customers.

Last year, I got a UK Business Visitor Visa. However, one of the guards at Border Force said that wasn't necessary since I was only coming up for meetings or to advise.

So question. Do I need a visa?

Thanks in advance

Yes actually you do need a business visa (and not a work visa), since you are only contributing through meetings and workshops and not actually spending 35 hours plus doing a job.

Source: Same situation between UK and Finland.