Remember the bus?

You probably know by now that it was wrong.

We don’t send £350 million a week to the EU. We get a ‘rebate’, basically a discount.

The correct figure is more like £250m, leaving aside the money the EU spends in the UK. Surely this figure would have been just as useful for Vote Leave’s argument?

Who knows. But in all fairness, researching the figures for the first time is a confusing experience.

The rebate is listed in the ONS Pink Book as a credit from the EU (rather than a negative debit), so it would be easy to assume that the money was sent to Brussels and then back. But it isn’t. The rebate is applied straight away and that “£350 million per week” never leaves the UK.

Our work trying to halt the claim

Our article became the top hit on Google if you searched “How much do we send to the EU?”. It was read five times more than any other factcheck we’ve written in the past six months.

We covered this several times on our own website, pushed out videos on Facebook, live-tweeted about it during debates, and appeared on multiple media news channels to debunk the claim.

And it wasn’t just us

As the claim gathered more coverage and more airtime, others decided enough was enough.

Eventually the ONS sent out a visual release clarifying what money goes where.

Then UK Statistics Authority said in an official statement that “the continued use of a gross figure in contexts that imply it is a net figure is misleading”.

Yet even this high profile, independent debunking wasn’t enough to undo the damage. Those responsible never corrected their statements, and pollsters Ipsos Mori found that about half of people who’d heard the claim believed it was true.

So, what needs to happen?

First, we need a clear statement from a regulatory body about misleading claims quickly after they appear in the public domain.

Second, once it’s clear a claim is misleading, journalists need to make sure their coverage doesn’t keep spreading misinformation. We have suggested to the BBC that they should alter their editorial guidelines to help with this. The guidelines should say clearly that claims shown to be false by the UK Statistics Authority will not go unchallenged when made on a BBC platform.

Finally, stopping the spread of inaccurate claims is partly about effective, fast rebuttal—but it's also about preempting inaccuracy in the first place. Full Fact has joined forces with the Economic and Social Research Council, the House of Commons Library, and the UK Statistics Authority, in the "Need to Know project".

It takes time to collect reliable data and to understand how it gets interpreted in the real world. If we can figure out what the debates will be now, information producers can lay the groundwork for accurate and informed debate—and effective rebuttal—in the years to come.

Find out more here.