A BIFF response is a reply to a hostile message that is Brief, Informative, Friendly and Firm. You answer the one thing that actually needs an answer, in a few calm sentences, and you leave out everything else: the defence, the counter-accusation, the history, the last word. It was developed by Bill Eddy, a lawyer, therapist and mediator who co-founded the High Conflict Institute, for exactly the situation many separating people are in: an ex who sends long, angry, blaming texts and emails, and a reply that will probably be read by a lawyer or a judge one day.

I’m a family mediator, and I teach BIFF to clients more than any other single skill, because the messages between separating parents set the temperature for everything else: the mediation, the children’s week, and, if it gets that far, the court file. This page explains the four parts, shows real-world examples of hostile messages and BIFF replies, covers what BIFF isn’t (it isn’t being nice), and how it fits into an Ontario separation. If you want the one-page version to keep beside your phone, the free cheat sheet and coaching video are at the bottom.

What is a BIFF response?

BIFF is a way of writing, not a way of feeling. Bill Eddy built it for what he calls high-conflict people: people who repeatedly blame others, see situations in all-or-nothing terms, and escalate rather than solve. You can’t change how that person writes to you. You can control what you send back, and a BIFF reply is designed so there’s nothing in it to fight about. His book, BIFF: Quick Responses to High-Conflict People, and the High Conflict Institute are the original sources; BIFF Response is the Institute’s registered trademark, and what follows is how I use it with Ontario separating couples, in my own words and examples.

The four parts

Brief

Keep it to a short paragraph, often two to four sentences. A long reply signals that you’re upset, gives the other person more sentences to pick apart, and invites a longer reply back. If their message raises ten things and only one needs an answer, answer the one.

Informative

Give the straight facts the other person needs, and the next step. Times, dates, amounts, what you will do. Leave out opinions about them, their new partner, their parenting or the marriage. If something in their message is false and it matters (because a lawyer will read it), correct it once, in one neutral sentence, with the fact. If it doesn’t matter, let it go.

Friendly

Friendly doesn’t mean warm or apologetic; it means not hostile. A neutral greeting, a “thanks for letting me know”, a “have a good weekend with the kids”. The point is to lower the temperature, not to win them over, and to make sure that anyone reading the exchange later sees one calm person.

Firm

End the conversation. A BIFF reply doesn’t invite more back-and-forth; it states the arrangement or offers two clear choices, with a deadline if one is needed, and then stops. You don’t have to reply again to their reply.

BIFF response examples for separated parents

These are composites of the kinds of messages I see in mediation files, with names and details changed. Read the hostile message, then the BIFF reply, and notice what the reply leaves out.

Example 1: the late pickup

Their message: “Typical. You were 40 minutes late AGAIN and Emma was in tears waiting at the door. You clearly don’t care about her. My lawyer is going to hear about this. Maybe you shouldn’t have her at all if you can’t even show up.”

BIFF reply: “Hi Sam. I was held up by an accident on the 401 and should have texted sooner; I’m sorry Emma had to wait. For Friday I’ll be there at 5:00 as scheduled, and if anything changes I’ll text by 4:30. Have a good week.”

What’s missing: no counter-attack, no “you’re always late too”, no response to “maybe you shouldn’t have her at all”. One short apology for the one thing that was real, then the plan.

Example 2: the support payment

Their message: “Where is the money?? It’s the 3rd. I can’t believe you’d make your own kids suffer just to punish me. Everyone knows what you’re like. I’m calling FRO.”

BIFF reply: “Hi Jordan. The child support payment for this month was sent by e-transfer this morning; you should see it today. Payments will continue on the 1st as set out in our agreement. Thanks.”

What’s missing: no defence of character, no reaction to “everyone knows what you’re like”, no comment on the threat. If the Family Responsibility Office calls, the facts are already in writing.

Example 3: the new partner

Their message: “I hear your girlfriend was at the house this weekend with MY children. You had no right. I never agreed to that and I’m not going to let some stranger raise my kids.”

BIFF reply: “Hi Alex. Yes, my partner joined us for dinner on Saturday. I understand it’s a big change for the kids and for you. If you’d like to agree on how we introduce new partners from now on, I’m happy to put it on the agenda for our next mediation session on the 14th.”

What’s missing: no argument about whether consent was needed. The reply confirms the fact, acknowledges the concern in one line, and moves a real disagreement to a place where it can be settled.

Example 4: the school decision

Their message: “I’m not signing anything for that French immersion program. You decided this without me like you decide everything. If you go ahead I’ll see you in court.”

BIFF reply: “Hi Pat. I haven’t signed anything; registration closes on March 1. The two options I see are: we enrol Liam for September and review it at the end of grade 1, or we keep him in the English stream at his current school. Can you let me know which you prefer by February 20? If we can’t agree, I’d suggest we take it to our mediator.”

What’s missing: no response to “like you decide everything”. Two clear choices, a deadline, and a next step if you still disagree. That’s what firm looks like.

What a BIFF response is not

The commonest mistake is to treat BIFF as being nice, or as a way to win the argument politely. It’s neither. Four things to leave out of every reply:

• Advice. “You should really get some help” or “maybe think about how this affects the kids” reads as an attack, however it’s meant.
• Admonishments. No telling-off, no “how dare you”, no “for the record”.
• Apologies you don’t mean. Apologize for a real mistake, once, in plain words. Don’t apologize to end the conversation; it reads as an admission.
• Sarcasm and emojis. They don’t survive being printed as an exhibit to an affidavit.

And one thing to consider before writing anything: does this message need a reply at all? A hostile message with no question in it, no change to the schedule and no deadline often needs nothing. Silence isn’t rudeness when there’s nothing to answer.

Why it matters in an Ontario separation

Three reasons, in order of importance.

First, the children. Section 7.2 of the Divorce Act requires each parent, to the best of their ability, to protect the children from the conflict of the proceeding. Children read their parents’ moods, and often their phones. Every exchange that ends in two lines instead of twenty is one less storm in the house.

Second, the record. In a contested Ontario family case, texts and emails between parents routinely end up as exhibits to affidavits. A judge reading a thread in which one parent writes in capitals and the other writes in calm, factual paragraphs forms a view about who to trust with decisions. Write every message as if a judge will read it, because one may.

Third, the agreement. Most separations settle, and the tone of the messages in the months before is the tone you bring into the room. Couples who’ve practised BIFF arrive at mediation able to negotiate. Many parenting plans now include a communication clause: written messages only, through a co-parenting app, about the children and logistics, with a reply time. BIFF is how you write inside that clause.

DARVO, and why BIFF works against it

DARVO is a term coined by psychologist Jennifer Freyd for a pattern people use when they’re confronted: Deny the behaviour, Attack the person raising it, and Reverse Victim and Offender, so the person who raised the concern ends up defending themselves. It shows up constantly in separation messages: you mention that the children came back without their medication, and three messages later you’re answering for everything you’ve done since 2015.

BIFF is the practical answer to DARVO because it refuses the reversal. You don’t defend yourself against the attack, and you don’t argue about who the real victim is. You restate the one fact that matters and the next step, and stop. If the pattern is constant and you’re afraid, that’s beyond what a communication technique can fix; tell your mediator or lawyer, and read our guide to divorcing a narcissist.

How to write a BIFF reply, step by step

1. Don’t reply straight away. Unless something is urgent for the children, wait an hour, or overnight. Hostile messages are written to get a fast reaction.
2. Find the one thing that needs an answer. A time, a date, an amount, a yes or no. Highlight it. Everything else is noise.
3. Write the facts and the next step. Two or three sentences. If a false statement matters, correct it once, neutrally.
4. Add one friendly line. A greeting at the start, a thanks or a “have a good weekend” at the end.
5. End firmly. State the plan, or give two choices and a date to reply by.
6. Delete the rest. Read it back and cut every adjective, every “always” and “never”, every reference to the past, and anything you’d be embarrassed to see in an affidavit.
7. If you’re not sure, have someone read it first. A friend who isn’t involved, your mediator, or your lawyer. Eddy recommends exactly this, and it’s the step most people skip.

When BIFF isn’t enough

BIFF lowers the temperature; it doesn’t make an unsafe situation safe. If messages include threats, if you’re afraid, or if the other parent is using contact to control or monitor you, keep every message, don’t engage, and talk to a lawyer about a protection or restraining order. In mediation, screening is designed to find exactly this, and where it does, the process changes: separate sessions, shuttle mediation by video, or a different process altogether. Our guide to the pros and cons of mediation explains when mediation isn’t the right choice, and the dispute resolution guide covers the alternatives.

Download the BIFF cheat sheet and coaching video

Ten points on one page to keep beside your phone, plus a short video of a coach writing BIFF replies to real hostile messages. Enter your email and they’ll arrive right away.

BIFF responses: common questions

What does BIFF stand for?

Brief, Informative, Friendly and Firm: the four qualities of a reply to a hostile message, in Bill Eddy’s method from the High Conflict Institute

It’s designed for written messages, texts, emails and co-parenting app posts, where your reply may later be read by a lawyer or a judge.

What is an example of a BIFF response?

A two or three sentence reply that answers the one practical question, gives the next step, adds a neutral courtesy and ends the exchange

For example: “Hi Jordan. This month’s payment was sent by e-transfer this morning; you should see it today. Payments will continue on the 1st as agreed. Thanks.”

Is BIFF just being nice?

No. BIFF is neutral, not warm. It leaves out advice, admonishments, insincere apologies and sarcasm, and it ends the conversation rather than inviting more

Friendly means not hostile. The goal is to lower the temperature and keep a clean written record, not to win the other person over.

Do I have to reply to every hostile message?

No. If a message has no question, no change to the schedule and no deadline, it often needs no reply at all

When a reply is needed, answer only the part that needs an answer. You also don’t need to reply to the response to your BIFF.

Can BIFF be used with a narcissist or high-conflict ex?

Yes, that’s what it was built for. It gives a high-conflict ex nothing to argue with, but can’t change them or make you safe

Keep every message. If there are threats or you’re afraid, talk to a lawyer about protection orders and tell your mediator before any joint session.

What is DARVO?

Deny, Attack, and Reverse Victim and Offender: a pattern described by psychologist Jennifer Freyd, where a confronted person turns the accusation back on the accuser

BIFF counters it by refusing the reversal: no defence, no argument about who’s the victim, just the one relevant fact and the next step.

Will my texts be used in court in Ontario?

Yes. In contested family cases, messages between parents are often exhibits to affidavits, so write every message as if a judge will read it

Calm, factual messages help your credibility; capitals, sarcasm and threats hurt it, whoever sent the first one.

Should we use a co-parenting app?

Often, yes. Many Ontario parenting plans require written communication through an app, about the children and logistics only, with set reply times

Apps keep a time-stamped record both parents can see, which tends to improve the tone on both sides.