There are several times during the year when you may need to hide the fact that you have bought something for your wife. Doing so can be more difficult than it sounds, though. This is especially true if you and your wife share a bank account and credit cards. She may not know exactly what you got her because of these things, but she can determine where her gift is from and how much it cost.
Avoid using direct deposit for your paychecks. If you use direct deposit, your wife will know when you have taken money out of the bank account to buy her something. This can ruin what would have been a great surprise. Instead, take small amounts of money from your checks weeks and even months ahead of time. This will allow you to save up the money you'll need for the purchase without your wife knowing what you've been up to.
Use PayPal to make purchases for your wife. PayPal can be an excellent place to store the money you've been keeping from your wife for such purchases. You can also use PayPal at many online stores. If you have a personal PayPal account, all you have to do is create a password that your wife will never guess. She'll never know when you use that account to make a purchase.
Never use a debit or credit card that the two of you share. Using your debit card isn't a good idea because she will be able to tell when you've taken money out of the bank account. A shared credit card isn't necessarily any better, though, especially if you two manage your account online. If your wife is one to snoop for a gift, she may check the account around special days like your anniversary or Christmas to see if you've made any purchases.
Sign up for online billing for any personal credit cards or other accounts you may have. Having a separate card won't do much good if you receive a bill in the mail and your wife gets to the bill before you do. Online billing works the same way as PayPal. Only you will know the password(s) you have created for these accounts, and thus only you will know what purchases you have made.
Make same-day purchases if you're buying a gift for your wife. Buy your wife's birthday gift before coming home from work, for example. Simply put, if you haven't made the purchase yet, you won't have anything to hide. This makes the task easier since it allows you more options when it comes to making your purchase.