The BIFF Method: How to Answer a Hostile Co-Parent

What BIFF stands for

BIFF is a communication method developed by the High Conflict Institute for responding to hostile messages. Each letter is a rule for your reply.

• Brief. A few sentences, not a wall of text. The more you write, the more there is to attack. Short gives them nothing to grab.
• Informative. Stick to useful facts. Correct wrong information calmly if you need to, but do not argue, justify, or explain your feelings.
• Friendly. A neutral, civil tone. Not warm, not sarcastic, just pleasant enough that no one could call it an attack. A simple "Thanks for letting me know" goes a long way.
• Firm. Close the loop. End with a clear statement or a yes or no question so the topic is finished and the door to more back-and-forth is shut.

That is the whole method. The hard part is not understanding it. The hard part is doing it when you are angry, which is exactly when you need it. This is a core piece of the larger toolkit in our guide to communicating with a difficult co-parent.

Before and after: real rewrites

Here is how BIFF transforms an actual exchange. In each case, imagine the hostile message just arrived, and look at the reply most of us want to send versus the reply that actually works.

Example 1: The accusation of neglect

They wrote: "You clearly do not care about the kids. Jordan came home with the same clothes AGAIN and no homework done. Do you even parent when they are there or just ignore them like you ignored me?"

The reply you want to send:

"That is completely unfair and you know it. I ALWAYS take care of them, unlike you who cannot even be on time for a single pickup. Jordan chose those clothes and the homework was not even assigned until today, so maybe check your facts before you attack me for once."

The BIFF reply:

"Thanks for the heads up. Jordan's homework was assigned today and is due Friday, so there is time to finish it this week. I will send a spare outfit in the bag going forward. Let me know if there is a specific assignment you want me to prioritize."

The second one corrects the facts without a single jab, and it ends with a question that moves things forward. Read side by side later, one parent is fighting and one is parenting.

Example 2: The schedule ambush

They wrote: "I am keeping the kids this weekend since you are always too busy with your new life anyway. Do not bother arguing, they want to be with me."

The reply you want to send:

"Absolutely not. This is MY weekend per the order and you do not get to just decide to steal my time because you feel like it. Stop putting the kids in the middle and stop lying about what they want."

The BIFF reply:

"This is my scheduled weekend under our current agreement, so I will pick up Casey and Sam at 5 on Friday as usual. If you would like to request a swap for a future weekend, I am happy to look at dates."

No accusation of lying, no fight about what the kids want, no mention of "the middle." Just the agreement, the plan, and an open door. It is firm without being hot.

Example 3: The late-night barrage

They wrote: "I cannot believe you took them to your mother's without telling me. You have no respect for me as a parent. We need to talk about this RIGHT NOW."

The reply you want to send:

"It is 11pm and I am not doing this again. Your mother sees them constantly and you never ask me, so do not lecture me about respect. Everything is a crisis with you."

The BIFF reply:

"The kids visited my mother on Saturday afternoon and are doing well. Happy to keep you in the loop on family visits going forward. I will respond to anything else in the morning."

Notice the last line. "Firm" can mean gently ending the conversation. You are allowed to not be available at 11pm, and saying so calmly is a boundary that reads perfectly clean on the record.

Common mistakes that undo a BIFF reply

The method is simple, but it is easy to slip. Watch for these.

• Sneaking in one jab. One sarcastic line at the end erases the whole reply. If it would sound bad read aloud in court, cut it.
• Over-explaining. The moment you justify your choices at length, you have handed them more to argue with. Brief is a discipline.
• Asking an open question that invites a rant. "Why would you say that?" opens a door. "Can you confirm Friday at 5?" closes one.
• Sending it while still angry. Even a perfect BIFF draft is worth a pause. Write it, wait, reread it as if a stranger sent it, then send.

That last one is where a tool helps. When a draft comes out sharper than BIFF, TextingParents can suggest a calmer, brief version before it sends, and because every message stays on the record, the contrast between a hostile message and your clean reply is preserved exactly as it happened. If the anger is the real obstacle, our guide to keeping texts civil when you are furious goes deeper.

Where BIFF fits with everything else

BIFF is how you answer. It pairs naturally with the gray rock method, which is about giving no emotional reaction at all, and it is a central tool when co-parenting with a high-conflict ex. Use BIFF for the messages that demand a reply, use gray rock for the tone, and let the record hold everything you choose not to dignify with a response.

The bottom line

You cannot stop a hostile co-parent from sending hostile messages. You can decide that your replies will always be brief, factual, civil, and final. That is BIFF. It de-escalates in the moment, it protects your energy, and it quietly builds a record where you are, message after message, the reasonable one. When in doubt, write less, correct the fact, stay pleasant, and close the loop.