Most people put real thought into their Will and almost none into a single line on their property deeds. That is a shame, because if you own your home with someone else, whether you are joint tenants or tenants in common helps decide what happens to it when one of you dies. In some situations it overrides what your Will says altogether.

It is one of the most common surprises we come across in a first meeting.

The two ways to own a home together

In England and Wales, two or more people can own a property together in one of two ways, and HM Land Registry sets out the difference plainly.

If you are joint tenants, you have equal rights to the whole property. None of you has a specific share in it. If one of you dies, the property automatically goes to the other owner or owners. And you cannot pass on your ownership of the property in your Will.

If you are tenants in common, each of you owns a specified share, and those shares do not have to be equal. Your share of the property does not automatically go to the other owners if you die. It passes under your Will instead. Worth knowing: the words "tenants in common" will not appear anywhere on your register, even when that is what you are.

Why your Will might not have the final say

Here is the part that catches people out. If you are joint tenants and your Will leaves "my share of the house" to your children, that gift generally cannot take effect. There is no separate share to leave. The property passes to the surviving owner automatically and your Will never gets a look in.

That is not a mistake in your Will. It is simply how joint tenancy works.

For plenty of couples, this is exactly what they want. If everything is going to the survivor anyway, joint tenancy is simple and it does the job. The difficulty only appears when someone assumes their Will is doing something it cannot do. The situations where that gap tends to matter most are:

• Second marriages, where you would like your share to go to children from an earlier relationship
• Friends, siblings or business partners who bought together and each put in a different amount
• Unmarried couples who want to look after each other and also provide for their own families

How to check whether you are joint tenants or tenants in common

One good place to start is your title register. You can download a copy from HM Land Registry for £7. If you hold the property as tenants in common, you should see an entry called a Form A restriction, which reads:

"No disposition by a sole proprietor of the registered estate (except a trust corporation) under which capital money arises is to be registered unless authorised by an order of the court."

If you are joint tenants, no Form A restriction is added to your register. The other place to look is the transfer form you signed when you bought the property. Panel 10 of the TR1 is where the choice was recorded, which is why HM Land Registry suggests double-checking that box before you ever sign it.

One important warning

A Form A restriction on its own does not prove you are tenants in common. If the ownership question was left blank or was unclear when the property was transferred, HM Land Registry has to enter a Form A restriction by default. There can be other reasons for it as well.

HM Land Registry is very open about this. Its own staff cannot tell you which type of owner you are, and it recommends checking with a solicitor or conveyancer if you are unsure. So treat your register as a strong clue rather than the final word.

Changing from joint tenants to tenants in common

You can change it, and you do not need the other owners' agreement. The process is called severance of a joint tenancy, and the written notice route comes from the Law of Property Act 1925. Section 36(2) says that a joint tenant who wants to sever "shall give to the other joint tenants a notice in writing of such desire".

Where the other owners do not agree, that means serving a written notice of severance on them, then applying to HM Land Registry to enter a Form A restriction using form SEV. There is currently no fee for the application.

Take advice before you change anything

People sever a joint tenancy for all kinds of reasons, and it can be a sensible part of a wider plan. It can also have knock-on effects that are not obvious at the time, which is why HM Land Registry itself recommends speaking to both a legal adviser and a financial adviser before making any changes.

Be cautious of anyone who tells you that changing how you own your home is a guaranteed way to protect it from a particular tax or cost. It is not that simple, and the right answer depends on your circumstances, who you want to benefit and what else is in your estate.

Our suggestion is more modest. Find out which one you are, then make sure your Will and your deeds are telling the same story. You can see how we help families with this across Wills, Trusts, Lasting Powers of Attorney and Probate.

A quick word on where you live

Everything above applies to England and Wales. Property law works differently in Scotland and Northern Ireland, so the position there will not be the same.

If you would like to talk through how you own your home and what it means for your family, you can book a free consultation with us. No pressure, just a friendly chat.

This article is general information for England and Wales, not legal or financial advice, and the rules can change. Please seek personal advice about your own circumstances.