<prompt> Human: My wife is a secondary credit card holder to simplify her purchasing needs food, petrol, coffee. The credit card account has a 55 day interest free period and zero annual fee. The catch is that the interest rate kicks in at 18 so the balance must be cleared each month to avoid interest charges.I earn about 6k per month and get paid monthly. I pay 1,400 in mortgage and our utility bills range from 100 to 3000 per month. We have previously tried to stick to a monthly credit card debt of 3000 per month as Ive found that often I can pay that even after paying all the other bills. The problem is that often she would spend well above 3k per month eg 4 - 5k. This prompted me to suggest managing a spreadsheet to keep track of the finances, but what I noticed is that it didnt seem to make a difference in her spending habits. We would review it weekly to try to stay on track for the month but it just didnt seem to make a difference. Basically, if she wanted it, she would buy it. This was worse around Christmas time when she would have the highest expenditure of the year. I have resolved this for the last 3 years by taking the credit card from her after Christmas to try to pay off the credit card as quickly as possible. This is very effective to get our finances our of the red.This year, she has once again spent up currently 7k on the credit card - and shes just gone shopping again and Im afraid to look. A potential solution I thought of was getting her own credit card with a 3k limit, but the problem with these cards is that they dont waive the foreign transaction fee we would get charged 3 when she makes international purchases - which happens often enough. The credit card she has doesnt get charged that fee.I dont want to pay the foreign trx fee just to keep her from over spending but Im thinking maybe someone else has a suggestion I havent thought of?Assistant: Australian here.I bank with Commonwealth Bank and you can set monthly spending limits on cards. Have you considered something like this? Might be a bit easier if she doesnt take to the take the card away as easy.Human: Yes, I wanted to give her her own credit card with a lower limit but I was concerned about the foreign trx fee for cards with low limits ie 3k. Also, the only 0 annual fee the common wealth bank has is the student credit card.  <response>: Are the foreign transaction fees going to be more than the thousands of dollars she goes over budget monthly? I assume not, so even if fees are charged youll be better off... 