GOV.UK
Undisclosed Partners: Balance of Evidence
It is not possible to lay down hard and fast rules about the weight and worth of the various criteria in establishing that a couple are living together. You will need to decide every case on its merits and on the balance of evidence. Sometimes the conclusion will be obvious, and at other times it will be a very fine judgement. Although you must consider each of the five criteria listed at CCM15040 you might not be able to gather evidence for each of them. For example the customer might say they have no idea what others think of their relationship.
If you are having difficulties in making up your mind about what the evidence means, you may find it helpful to list the evidence on both sides of the argument. This should help you identify where the balance of evidence lies - though you should not base your decision on a crude numerical assessment, as some elements of the evidence may be far more critical than others.
If you still cannot decide, you may want to discuss the issues with your manager, or with another colleague in your team. If the issues are particularly difficult, you may, after consulting your manager, want to refer to your Claimant Compliance Group Manager.
Where there is no reply to your opening letter - see CCM15370.