I have been studying and researching the Employment Services Act (ESA) for over seven years, and have attended numerous legislative and police department conferences which discussed the enforcement details in depth. Hence, I feel I can speak with some element of authority on this subject.
Residency rights and work rights in Taiwan are (at the present time) separate considerations. If you are a foreigner working in Taiwan, then you need a work permit.
If you are working in Taiwan, then you are supposed to pay tax on the income received for those services. The payment of salary/wages etc. to a Taiwan employee’s foreign bank account, as an attempt to avoid ROC income tax liability, is illegal according to the ROC Income Tax Law. Again, what that means simply is: ALL SALARY/WAGES PAID for services rendered in Taiwan should be reported on your ROC income tax return, to be filed on or before the end of March every year.
Although you have not specifically stated your “intended working style” as a consultant for local companies, I get the impression that you are going to go sit in the office. Is that correct? If you are doing all your consulting work at home, and then just emailing it in, or snailmailing it in, or perhaps dropping it off during your afternoon leisurely walks in Taipei (or wherever) then I would adise that you don’t need a work permit anyway.
Is the UK Consulting Company in question planning to set up a Taiwan office? If you had a full-time work permit to work for them, that might simplify matters a lot, since during your travels around town you would just be calling on clients, attending meetings, etc. It could then be assumed (for the sake of applying for the work permit) that most of your actual work was done in the local consulting office.
I have a strong interest in seeing Taiwan become more internationalized. Since I have been married to an ROC national over 12 years, I have often lobbyied for less restrictive laws and regulations on “foreign spouses.” I work with the legislative, executive, and judicial branches of the ROC government. Over the years however, I have regretted that no one from the foreign business community, or from the foreign community at large, has ever come forth to liaison with me in order to advance their own agenda.
I really feel that many of the issues you raise, and the problems you are encountering should be dealt with in a more comprehensive fashion. However, it is a big job and needs a dedicated group of interested and informed people to take charge and move forward.