An offset tracker mortgage works on the basis of the borrower's savings. In general, most borrowers wanting to draw a mortgage have some savings just in case. However, those savings can earn sky-high interests if you keep them at the bank. An offset tracker mortgage can help you get rid of those interests and of the lien itself. Since the rate of the offset tracker mortgage is linked to the base rate of the Bank of England, this eliminates the risk of falling for predatory practices.
There are companies who take advantage of borrowers who do not draw an offset tracker mortgage by charging them sky-high interest rates and by changing them whenever they please. With an offset tracker mortgage, companies cannot touch interest rates.