But, remember that London Heathrow is only one of the airports in London – searching for flights from ‘London’ to ‘London’ will give you more options, and possibly lower prices.
You could also try searching by month, if you're flexible on dates. This will show you when prices are at their cheapest and their most expensive. Generally speaking, the earlier you book, the better deal you'll get.
We don't just compare flight prices. If you need to book accommodation for your trip, or you want to hire a car to explore United Kingdom, we've got some options for you to compare. Plus, when you sort your flights and hotel in one booking, you could save even more.