The flat rate scheme lets you charge VAT normally but pay HMRC a fixed percentage of your gross turnover instead of the difference between output and input tax, and you generally cannot reclaim VAT on purchases. It exists to simplify, not to save, though it sometimes does both. It works for service businesses with few costs — a consultant with a laptop and a phone. It works badly for anyone with significant VAT-bearing purchases, because the input tax you forgo exceeds the saving. The limited cost business rules push businesses with low goods spend onto a high percentage that removes most of the benefit, and they catch more people than expected. Worth modelling on your actual figures rather than assuming; we can run it in an afternoon.