There is no right or wrong way to deal with finances, especially in a relationship, so that is the first thing to remember. Especially as there are so many different variations of relationships - such as blended families, new relationships, irregular earning patterns, no children, some children, etc. Its also important to remember the risk and legal side of this. For marriages and civil partnerships your assets are generally treated as fully combined anyway - but if you are outside of these legal structures you do not have that protection.
If you are in relationship where you feel this could work for you both but at the moment you have separate finances, here are some good reasons why you could consider combining finances:
Il'l do it if you do it...
1. It can give you a feeling of abundance
If you currently have separate finances where wages go into separate personal accounts then you put money in the joint account, you don't have a full picture of your total income as a household. This means that when you are tackling life goals together and you look at the money in the joint accounts, you may feel there isn't enough to hit your joint goals. In reality, you actually have more income at your fingertips to throw at goals, you just don't realise because its not there right in front of you - its scattered around the place and probably leaking from the household without thought.
2. It keeps things simple
The key to doing well financially is knowing your numbers i.e. what comes in and what goes out each month, and doing this in a really simple way. If you have 3 or 4 different current accounts in the relationship - how can you accurately know your numbers? Practically, having everything coming in and going out in one account is the clearest way to both have full knowledge of your numbers.
3. It balances the relationship
Taking the step to pool your finances fully is an acknowledgement that your income is for "us" and not "me". This can really help where there is a big difference in income amounts. For example, if one person is out of work or on a low income for a period of time, the joint income is seen as reduced rather than one person contributing less. This is generally the position legally anyway for most legally connected couples.
4. You can still have "me" money
Some people say that "I want to spend my money how I want". That's absolutely fine. Put it in the budget, say £50 or £500 - whatever you jointly decide is right in the family - and withdraw that in cash each month or put on another card and use it as you wish. This isn't about taking away your ability to spend on yourself, its about deciding that amount together after pooling resources. Its probably doing what you're doing now - but the other way round. Joint account first - personal account second.
5. It can bring you closer together
It is actually very satisfying and freeing to give your income to the household and work together on how the combined money should be treated. Building a budget plan together is a really nice thing to do - get a glass of wine each and sit at a table and build an amazing plan together. You won't believe what a great bonding experience it can be.
It won't work for everyone, and there's lots to consider around issues of trust, risk and legal protection of your money, but if you are in a relationship where this could work, why not consider giving it a go? I guarantee that working as a team, with all money combined, you will smash your life goals quicker than ever.