I recently moved out of my parents’ house and in with my boyfriend of four years. We are both in our early twenties, and sincerely want to build a life together. My boyfriend is terrible with money, but thankfully he is aware of his problem. He will spend wastefully, and use his debit card for small purchases and forget to keep the receipts. This makes it difficult for him to balance his checking account and often results in pricey overdrafts that we really cannot afford to pay. He has offered to let me "take over" the finances by suggesting that we get a joint checking account which would be my responsibility to manage. On the one hand, I like the idea of being able to see where our money is going, discussing our purchases together, and seeing where we can cut expenses and save money for our future together; but on the other hand, I am afraid that he will start using my money as a cushion to prevent his frequent overdrafts, and that any attempts to get him to budget will fall upon deaf ears. I need some guidance - quick!
In reading (and re-reading) your letter, I notice three things. The first is your use of the word "his" when referring to the problem behavior - his problem with money; the second is your use of the personal possessive "my" when referring to the other side of the coin - "my money as a cushion…” The third is your use of the words "we" and "our" when referring to future events. This tells me that even though you are looking towards building a life together, you are still not completely out of the "yours and mine" mindset as opposed to thinking in terms of "ours" - as in "our money" - at all times.
Since you are living together, I would strongly recommend having a joint checking account, into which you each deposit an equal percentage of your paychecks. Keep this account for bill paying only. You could also open a joint passbook savings account (with no debit-card attached to it) into which you each deposit an equal amount of money each paycheck. This way, your joint finances will go towards building the future you seek by creating a sense of equal financial responsibility towards each other without destroying your credit in the process (some banks report repeated overdrafts to the credit bureaus).
When it comes to personal expenses, each of you should have separate spending accounts - and I would recommend pre-paid debit cards, to prevent overdrafts - that allow you the flexibility you need without cheating your household budget. I realize this sounds rather complicated, but the merging of finances generally is, especially when one partner is frugal and the other a spendthrift.