Taking aside you aren't going to get much of a loyalty discount whilst leaving...Plusnet use a 'profit forgone' termination fee, so it's probably not £90, i.e the remaining bills. Plusnets early termination fees are based on how much it costs them to provide for said length of time before they make any money on it. The per month charges are here from 2019, though price changes have occurred since then so it won't be exact but may give an idea if you work it out based on the product you have
https://www.plus.net/help/legal/plusnet-price-guide-for-residential-products/The actual per month fee should be in your contract, but if you want to get an accurate number you'll need to actually speak to them directly-give them a call and they be able to give you a figure for on that day.
