In the second paragraph of his short judgment (agreeing with Lord Wilson and the other five SCJJ with whom they sat) Lord Neuberger – in Gohil v Gohil  UKSC 61 (14 October 2015) – summed up Gohil and Sharland v Sharland  UKSC 60 (14 October 2015)) thus:
 … where a party’s non-disclosure was inadvertent, there is no presumption that it was material and the onus is on the other party to show that proper disclosure would, on the balance of probabilities, have led to a different order; whereas where a party’s non-disclosure was intentional, it is deemed to be material, so that it is presumed that proper disclosure would have led to a different order, unless that party can show, on the balance of probabilities, that it would not have done so.
If you didn’t disclose because you didn’t know (like the wife in Livesey (formerly Jenkins) v Jenkins  AC 424,  FLR 813 who didn’t know she had to tell everyone she was about to remarry), then it is for the spouse who seeks to set aside the order to prove it. (Mr Jenkins successfully did prove his point.) If you deliberately hide facts then the order will be set aside when you are found out, unless you can show that the hidden facts would have made no difference: ‘see per Lady Hale in Sharland v Sharland  UKSC 60, paras 29-33’ said Lord Neuberger.
I think Lady Hale was a bit stronger than that; but for most of us Lord N’s § is a fair summary of the two cases. There is some procedural stuff I need to write up; and it is said that Family Procedure Rules Committee are looking at re-writing the rules – but then they’ve been doing that for three years and more. I’ll keep you posted on any movement there.
I am pleased that Briggs LJ was right (as I said I thought he was: https://dbfamilylaw.wordpress.com/2014/02/11/sharland-a-failure-of-legal-principle/). If people tell lies, it’s much better if they are not allowed to get away with it. And if a party gets it wrong, but not because it was a lie, you may have more of a struggle to set aside an order. Either way it’s an application to set aside (ie not an appeal): the applicant is not saying the judge who made the original order got it wrong on the facts at the time (Peek v Peek  2 AllER 297, Lord Merriman P).