Question: If my fiance and I want to obtain a zero percent interest rate credit card to finance some elements of our wedding, what pitfalls should we be aware of? Can the bank change the promotional zero percent intro rate?
Answer: I don't really understand in what way you mean "can the bank change the promotional rate?" Do you mean by extending or shortening the period of time it is in effect? If that's it, the answer to your question is that it can be changed but usually will not be.
A credit card issuer can change anything within the contract with a simple letter to you and usually 45 days notice. Normally you are given the option to opt out of the change by closing the account, but you must continue to pay off your balance before the card is officially closed and you will no longer be able to use the card once you opt out, regardless of how long you take to pay off the balance. Changes of contract usually occur in the first or last quarter of the year and are usually mailed out under the heading "change of terms notice."
If you are trying to determine whether your zero per cent introductory offer will be rescinded, it can be but probably will not be. But I caution getting a card simply for a long term introductory offer. Introductory APRs end, and when they do, the consumer is stuck paying whatever interest was agreed to in the body of the contract. That is why these are called "teaser rates." They are an inducement or enticement to get a card with the hopes you will not pay off your balance, and they can gain back their lost revenue from the introductory enticement.
It is not recommended that you utilize a teaser rate for any reason other
than differentiating between two very promising offers unless you are two
exceptionally well-disciplined individuals and committed to paying off the
balance within the specified time period. On that note, perhaps you might want
to consider whether you really want to start off your marriage with any debt at
all. However, now that the Credit CARD Act of 2009 is effective, banks have to adhere to strict restrictions related to teaser rate terms and changes.