As an attorney, my answer is almost always going to be “get it in writing.” While you may have the most amicable divorce in the world, you never know what the future may hold. Contracts fill the gaps left when human trust fails.
If this is a one-time, or two-time situation, a verbal agreement might suffice. Of course, without putting it in writing, if you agree to a “quick change,” you may find yourself agreeing to a years-long arrangement without intending to.
Moreover, while it is hard to think about, custody agreements in part to protect children from the threat of parental abduction. Without having a firm time or day for the hand-off, you might find yourself more anxious for the return of your children than you need to be.
If this is a longer-term change, you should definitely alter the custody agreement. If both parents agree to the change, they can jointly file a petition with the court in a fairly simple process.
Whether you are working out an initial custody agreement or need to modify one that is no longer working for your family, come discuss your individual situation with our skilled family law attorneys.