What Common Law Marriage Means for Pet Owners in the UK
Ask most people in the UK whether they have heard of common law marriage and most will say yes. Ask them what it actually means legally and most will get it wrong.
The belief that couples who live together for long enough acquire legal rights similar to married couples is one of the most persistent legal myths in the UK. It has real consequences for pet owners, because the rights people think they have when a relationship ends are often not the rights they actually have.
Common law marriage does not exist in England and Wales
This is the most important thing to understand. There is no such thing as common law marriage in England and Wales. It does not matter how long you have lived together, whether you own property jointly, whether you have children together or whether you refer to each other as husband and wife. Cohabiting couples in England and Wales have no automatic legal rights equivalent to those of married couples when a relationship ends.
This has been the legal position for centuries and it has not changed despite repeated calls for reform. The Law Commission has recommended reform on multiple occasions. Parliament has not acted. As of 2026, cohabiting couples in England and Wales remain in a significantly weaker legal position than married couples in almost every area of relationship law.
Scotland is different. The Family Law (Scotland) Act 2006 gave cohabiting couples in Scotland some rights on separation that do not exist south of the border. Our guide to what happens to pets in a divorce in Scotland covers the Scottish position in detail.
What this means for pet owners
For pet owners, the absence of common law marriage rights means that when an unmarried relationship ends, there is no formal legal process for dividing shared property. Everything comes back to the fundamental question: who owns it?
For a pet, ownership is determined by the factors our guide to whether a microchip proves you own a pet covers in detail: purchase documentation, microchip registration, vet records and, following the FI v DO ruling, caregiving history.
An unmarried couple who have shared a pet for five years have no more formal legal claim to a division of that pet's care than a couple who have shared a pet for five months. The duration of the relationship does not create rights. What creates rights is evidence of ownership and caregiving.
The cohabitation trap
The myth of common law marriage creates a specific problem for pet owners. Couples who believe they have legal rights they do not actually have may not take the practical steps that would protect them if the relationship ended.
They do not create a petnup because they assume the law will sort things out fairly. They do not think carefully about whose name the microchip is registered in because they assume it does not matter in a long-term relationship. They do not keep a caregiver log because they assume their years of involvement speak for themselves.
When the relationship ends and they discover the legal reality, they are in a worse position than they would have been if they had understood the law from the start.
The protection that actually works
Since the law provides limited protection for unmarried couples sharing a pet, the most effective protection is the kind you create for yourself.
A petnup created while the relationship is good is the single most effective step an unmarried couple can take. It creates a written record of what both people intended and agreed, made at a time when neither had any reason to be strategic. If a dispute ever arises, that document is the strongest evidence of what was decided.
A caregiver log maintained consistently throughout the relationship creates an evidential record of day-to-day caregiving involvement that no amount of time alone can provide.
Making sure the microchip registration, vet records and insurance all reflect the reality of primary keepership provides the documentary foundation that a court or mediator would look for.
Our guide to pet custody rights for unmarried couples covers all of these steps in detail.
The calls for reform
The legal position for cohabiting couples is widely acknowledged to be unfair and out of step with social reality. Cohabiting couples are the fastest-growing family type in the UK. Millions of couples live together for years or decades, share finances, raise children and own pets together with no more legal protection than strangers.
The Cohabitation Rights Bill has been introduced to Parliament on multiple occasions and has not yet become law. The government has committed to consulting on cohabitation law reform as part of broader family law review. Progress has been slow.
In the meantime, the legal position remains as it is: cohabiting in England and Wales creates no automatic rights, regardless of how long the relationship has lasted or how intertwined the lives of the people involved have become.
What to do if you are in a long-term cohabiting relationship
If you are in a long-term cohabiting relationship and share a pet, the practical steps are straightforward.
Create a petnup now if you do not have one. The length of the relationship does not make a petnup less necessary. If anything, a long relationship in which a pet has become deeply embedded in both people's lives is one where a dispute would be particularly damaging and a written agreement is particularly valuable.
Make sure the documentary record reflects the reality of your arrangement. Check the microchip registration, the vet account and the insurance policy. If they do not reflect who is actually caring for the animal, consider whether to update them.
Start or maintain a caregiver log. A log that covers an extended period of a relationship is powerful evidence of sustained caregiving commitment that goes beyond what any single document can show.
The bottom line
Common law marriage does not exist in England and Wales. The legal rights most unmarried couples assume they have do not exist. For pet owners, this makes written agreements and documented caregiving history more important, not less.
Pawsettle helps unmarried couples create a petnup and maintain a caregiver log. It is not a legal service. For advice on your specific legal position please consult a qualified family solicitor.