1. Civil partnerships still cannot be converted to marriages.
Same-sex couples who are already in a civil partnership will not be able to convert their relationship to marriage until later in 2014, while the government works out the official procedure for switching status.
Since civil partnerships can only be dissolved if both parties prove to the court that a relationship has broken down there is no way for couples to swiftly end their partnership and then remarry.
2. Northern Ireland has no plans to introduce same-sex marriages.
3. There will still be a spousal veto for married transgender people in England and Wales.
A clause in the England and Wales same-sex marriage bill requires the partner of a married transgender person to give written permission before a Gender Recognition Certificate be issued. This is a crucial piece of paper that restores some of an individual's rights that are lost when an person changes gender in the eyes of the law.
This means that for the first time a couple can change their legal gender without having to end their marriage.
But if a trans individual's partner refuses to give written permission then the trans individual is left in limbo. The only other way to gain a Gender Recognition Certificate is to get divorced, which can be drawn out and delay the restoration of basic rights.
The trans community has branded this clause the "spousal veto" and unsuccessfully campaigned to have it removed from the draft law as it made its way through the House of Commons.
Scotland has no spousal veto in its version of the legislation.
4. It's legal to pay same-sex couples less pension income than straight couples if a partner dies.
Many public sector pensions offer "survivor benefits" worth thousands of a pounds a year to spouses if the pensioner dies. Traditionally these benefits have been more generous to widows than widowers. When civil partnerships were created most pension schemes decided that all same-sex couples would receive the lower, widowers rate.
To make things worse for same-sex couples it is still legal to only consider pensions contributions from 2005 onwards when dealing with LGBT partners.
Peter Walker lost a recent test case on this issue after a tribunal decided that this stance is compatible with equality legislation. Walker claimed that his male partner would only receive £500 a year in the event of his death; if he had married a woman she would have been entitled to £41,000 a year.
This imbalanced arrangement will carry over from civil partnerships to same-sex marriages, although the government has said that it will review the rules.