This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Claimant Compliance Manual

Undisclosed Partners: Customer Has Been Involved in Different Relationships

Where the customer has been involved in relationships with different partners at different times during the year, you should treat the ending of one and beginning of another as a CoC on each occasion. However, where the customer has split up and reconciled with the same partner, you should normally ignore the splits and treat the customer and partner as a couple throughout the period.

If the customer objects to this approach you should consider whether in spite of the temporary break in the relationship, the customer and partner would still be considered a couple in accordance with other relevant criteria eg. nature of any financial support. If you cannot establish that the couple were effectively living together throughout the period, you should apply the CoC provisions to each break in the relationship.