By Julian Knight
BBC News Personal Finance Reporter
From Monday, same-sex civil partnerships will be recognised in law with major implications for tax and benefits.
Same-sex couples will enjoy enhanced rights
Under the Civil Partnership Act 2004 (CPA), same-sex couples who go through a civil partnership will be able to transfer assets between themselves with no more tax liability than married couples.
However, the rules limiting married couples' options on tax will also apply to civil partners.
Pension tax legislation has also be amended to include civil partners.
Registered civil partners will be able to make gifts or bequests to their partners with the benefits of Inheritance Tax (IHT) or Capital Gains Tax (CGT) exemption and will have their own form of married couple's allowance.
But also on a par with married couples, civil partners will not be able to get away with dodging tax by transferring their income to others who pay less tax.
CIVIL PARTNERSHIP RIGHTS
Social security and pension benefits
Possible parental responsibility for partner's children
Full recognition for life assurance
Responsibility to provide reasonable maintenance for partners and children
Same tax treatment as married couples, including exemptions from inheritance tax on homes
Visiting rights in hospitals
There are special rules already in place for husbands and wives, and these will be extended to same-sex couples.
From this month, civil partnership ceremonies will take place in front of a registrar and two witnesses at registry offices throughout the UK.
"In essence, civil partnerships will have the same legal weight as marriages, apart from one major difference, and that is that the ceremony will not be carried out in a church or other religious place," Barbara Simpson, partner at family law firm Boodle Hatfield.
"The UK has chosen not to go down the same route as Holland and Canada and allow gay marriage, but from a rights point of view, civil partnerships are just as good," she added.
Interestingly, the way that civil partnership rules are framed allows any two people of the same sex to enter into a civil partnership.
In short, people do not have to be involved in a same-sex sexual relationship to become same-sex civil partners.
Two platonic same-sex friends could enter into a civil partnership and be treated for all intents and purposes as a married couple.
And under civil partnership rules, unlike a marriage, non-consummation is not grounds for annulment.
However, there is a rule barring people from entering into a civil partnership with close family members.
"You can enter into a partnership with a friend or even your cousin but not with a sister, brother or parent," Ms Simpson said.
Civil partnership comes with potential drawbacks and responsibilities.
Elton John has said he plans to enter a civil partnership
The rules governing distribution of property on dissolution of a civil partnership are identical to those on divorce.
Civil partners on dissolution can claim a lump sum transfer of property, pension share and even maintenance payments for life.
Reacting to this, insurer More Than is offering to draw up civil partnership contracts, similar to pre-nuptial marriage agreements, for same-sex couples looking to enter civil partnership.
"The same as with marriage, you are entering into something which brings responsibilities that could go on for the rest of your life," Ms Simpson said.