How to write to your co-parent without starting a fight

You need to ask your ex for something ordinary, a swapped weekend or half the cost of soccer cleats, and you’ve rewritten the text three times because you remember how the last one went. Most of the fix is mechanical: one topic per message, one clear question with a date on it, nothing about the past, and a plan for when the reply comes back hostile.

None of this will make a difficult person reasonable. It does leave them less to argue with.

Why a two-line text turns into a fight

In person, your face and voice tell the other parent how to take a sentence. A message has neither, and the Department of Justice Canada’s guide to parenting arrangements warns that without those cues the same words can be read in a way you never meant. “Can you be on time Sunday?” feels fair when you type it. Read by someone tired and braced for criticism, it says “You’re always late.”

After a separation, every message also carries the old arguments. And as the same guide notes, a sent text can’t be taken back off the other person’s phone.

Build every message around one question

Decide what you need and write that sentence first. Then:

1. One topic per message. A dentist appointment and a birthday party are two messages. The Co-Parenting Communication Guide from the Arizona chapter of the Association of Family and Conciliation Courts (AFCC) suggests about one paragraph of five sentences.
2. A subject line naming the child and the issue: “Maya: dentist, March 3,” not “Re: re: Saturday.” New topic, new thread, so you can find the summer camp agreement in June. In a text, make it the first line.
3. A specific question. “Thoughts?” invites an essay. “Can you do pickup at 4 instead of 5 on Friday?” invites a yes or a no.
4. A deadline with a reason: “Could you let me know by Wednesday so I can book it?”
5. An easy yes: two options, or what you’ll do if you don’t hear back.

Money gets its own message. Justice Canada and Cafcass, the service that advises family courts in England, both suggest keeping money apart from messages about the children. A reimbursement request tucked into a note about the school play tends to swallow the school play.

Anything difficult, like a change of school, goes better as a conversation. Cafcass suggests asking to talk, agreeing a time and place, and setting an agenda so there are no surprises. If talking isn’t safe, stay in writing.

Reply times you can both live with

The AFCC guide suggests replying within 24 hours, even just to confirm you got the message, and no more than two emails a day outside emergencies. Agree on your own numbers (a parent on night shifts may need longer), so a day of silence stops meaning something. A workable default:

• Routine questions get an answer within 24 to 48 hours, even if it’s “I’ll know by Thursday.”
• Emergencies get a phone call first and a written note after. The AFCC guide’s example is to tell the other parent within two hours.

The High Conflict Institute advises against late-night texting with a high-conflict ex. Write it at 11pm if you must, and schedule it for 8am.

Templates for the messages you send most

These are written to Dan, co-parent of Maya, 8, and Leo, 13. Swapping a weekend:

Subject: Swap request, weekend of October 10

Hi Dan, my sister’s wedding is on Saturday, October 10, which is your weekend with the kids. Would you swap so I have them October 9–11 and you have them October 16–18? I’ll do both pickups. Could you let me know by September 25? If it doesn’t work, that’s fine; I’ll ask about having them for the afternoon instead.

Sharing school information. Ideally the school emails you both, and either of you can ask the office to set that up. Until then, forward the school’s own email rather than summarizing it.

Subject: Maya: parent-teacher conference, October 20

Hi Dan, Maya’s parent-teacher conference is Tuesday, October 20. The open slots are 4:15 and 5:30; I’ve forwarded the school’s email with the sign-up link. Happy to go together or separately. Could you tell me by Friday which slot you’d like?

A medical update covers what the AFCC guide lists: diagnosis, medicine and how to give it, side effects, warning signs and follow-up.

Subject: Leo: urgent care, ear infection

Hi Dan, I took Leo to urgent care this afternoon with ear pain. It’s a middle ear infection. He’s on amoxicillin twice a day until Tuesday evening; the bottle and instruction sheet will be in his bag on Friday. The pharmacist said to call the doctor if he gets a rash. If he still has a fever on Saturday afternoon, he needs to go back.

Asking for reimbursement, in a message of its own (more in how to split your child’s costs):

Subject: Expense: Maya’s fall swim lessons

Hi Dan, Maya’s fall swim lessons came to $180, receipt attached. With our 50/50 split, your half is $90. Could you send it by September 30? Thanks.

What never goes in writing

Both the AFCC and Justice Canada guides offer the same test: write as if a judge will read it. Add one more reader, your child at seventeen, scrolling through an old phone.

Leave out:

• Insults and labels, including amateur diagnoses like “narcissist.” Once your sentences start with “you always” or “you never,” the AFCC guide says, you’ve slid into blame.
• Your child’s private words used as evidence: “Maya told me she hates going to yours.” It makes her a witness against a parent she loves and teaches her to stop confiding in you. If what she said worries you, take it to her doctor or school counselor.
• Threats, even half-meant ones: “Keep this up and we’ll see what the judge thinks.”
• Legal posturing: clause numbers, “my lawyer says.” If the order matters, state it once, plainly: “The order has Leo with me for the second half of summer break.”
• The past. Write about what happens next.
• Extra readers. Justice Canada says to address messages to the other parent only, so new partners and grandparents stay off the CC line.
• Capitals for emphasis. Justice Canada’s guide calls it shouting.

Don’t send messages through your children

“Tell your dad I’ll be there at five.” For the child, a shortcut like this means standing between two people they love, watching each face as they deliver the news.

The Family Justice Young People’s Board, children and young people who have been through family court, put it plainly: “Don’t use me as a messenger between you and my other parent.” HealthyChildren.org, from the American Academy of Pediatrics, says children shouldn’t be go-betweens or be pumped for information about the other home.

A 1991 study in Child Development led by Christy Buchanan interviewed 522 adolescents about four and a half years after their parents separated. Those who felt caught between their parents were adjusting worse, and parental conflict was linked to adjustment only through that feeling. The abstract doesn’t single out message-carrying, but delivering adult business is one of the plainest ways a child ends up caught.

Younger children take the job literally and feel responsible when the answer is angry. If Maya, 8, comes home with “Dad says you have to pay for the school trip,” take it off her:

Thanks for telling me. That’s grown-up stuff, so I’ll text Dad about it myself. You don’t have to carry messages for us.

Teenagers can make some of their own plans: Leo, at 13, can ask his dad about a sleepover himself. Negotiating a weekend swap is a different job, and the other house may hand it to him too. Give him a line:

If Dad asks you to tell me something about money or the schedule, you can just say, “Can you text Mom?” You won’t be in trouble with me.

When a hostile message lands

Read it once and put the phone down. Unless it’s urgent, reply in the morning, and draft it in a notes app so it can’t go out by accident.

Decide whether it needs a reply at all

That question is the High Conflict Institute’s rule number one. Find the part that needs an answer (a date, an appointment, a decision) and ignore the barbs. A demand you’ve already answered needs no reply, or at most a shorter version of your last one. In one of the Institute’s divorce examples, a text full of insults and court threats, the recommended reply is nothing.

The exception is a wrong fact that could matter later, like a pickup you supposedly missed. Correct it once, in a sentence.

If it does, use BIFF

BIFF stands for Brief, Informative, Friendly and Firm. Bill Eddy, a lawyer and therapist who co-founded the High Conflict Institute, created it for hostile emails and texts. Keep it short: long explanations give the other person more to react to. Stick to information, not opinions or self-defense. Open or close with something friendly. Then end the exchange, or give two choices and a reply-by date.

Leave out what the Institute calls the three A’s: advice (“you just need to…”), admonishments (“you’re overreacting”) and apologies. Plain manners are the exception. “Sorry I was late” is fine; “I’m sorry you’re upset” reads as taking the blame.

Rewrite one: answering an accusation

Sarah’s message about their six-year-old, Ava, Thursday at 9:40pm:

You were 25 minutes late AGAIN on Sunday. Ava sat by the window in her coat crying. If you can’t manage a simple pickup maybe she shouldn’t come to you at all. My lawyer will hear about this.

The reply you want to send:

There was an accident on the highway, which you’d know if you ever read your messages. You were an hour late in March and I said nothing. Tell your lawyer whatever you like.

A BIFF reply, sent Friday morning:

Hi Sarah, thanks for letting me know Ava was upset, and sorry I was late. There was an accident on the highway and I texted you at 4:50 to say I’d be delayed. From now on, if I’m running more than 10 minutes behind, I’ll call instead. See you at 5 on Sunday.

It apologizes for the lateness and nothing else, gives one checkable fact, offers a change and ignores the lawyer. If Sarah does keep Ava from you, that’s for a lawyer, not a text.

Rewrite two: a request you wrote while angry

The draft:

Leo came back AGAIN without his inhaler. He’s 13 and has asthma, so I don’t know what goes on at your house but this is SERIOUS. You obviously don’t care. If this happens one more time I’ll have to do something about it.

The version to send:

Subject: Leo: inhaler

Hi Dan, Leo’s blue inhaler didn’t come back with him on Sunday. Could you check whether it’s at yours and put it in his school bag tomorrow? To stop this happening, I’d like to ask Dr. Hughes for a second inhaler so there’s one in each house. Could you let me know by Friday if that’s OK? If I don’t hear, I’ll go ahead. Thanks.

The worry in the draft is fair, and the second version keeps it. What it drops is the verdict on Dan, the only part he would have answered.

When writing to each other stops working

If a simple question takes ten messages, or your child asks what the fighting is about, better wording won’t fix it alone.

Narrow the channel first: one place for everything, and texts only for confirming pickups and emergencies, a limit Justice Canada’s guide offers as an example. Some parents move to a co-parenting app; Lullia, the app behind this blog, records messages with server time and doesn’t allow edits or deletions. (For what else to keep, see what to write down when you co-parent.)

Then bring in a third person. Cafcass suggests mediation for parents struggling to communicate; use it to agree your rules in writing, such as which channel and how fast you reply. Some US states and British Columbia let a court appoint a parenting coordinator for parents in ongoing conflict. If even businesslike messages become fights, parallel parenting cuts direct contact to the minimum the children need.

If messages threaten you or the children, or you’re afraid of your co-parent, tone is not the priority. Don’t reply to threats; save them and talk to a domestic abuse advocate or a family lawyer. In the US, call the National Domestic Violence Hotline on 1-800-799-7233 or text START to 88788. In England, Refuge runs the free 24-hour National Domestic Abuse Helpline, 0808 2000 247; Scotland (0800 027 1234), Wales (0808 80 10 800) and Northern Ireland (0808 802 1414) have their own lines. In Canada, ShelterSafe.ca, from Women’s Shelters Canada, lists crisis lines by province and territory. In an emergency, call 911 in the US or Canada and 999 in the UK.

Before you press send

• Is it one topic, with a subject line naming the child?
• Is there one clear question and a date to answer by?
• Could you delete the first paragraph and lose nothing?
• Is there anything about the past or their character?
• Are you quoting something your child told you?
• Would you be comfortable with a judge, or your child, reading it?
• Is it after 10pm? Schedule it for the morning.

This is general information, not legal advice. If your court order or parenting plan sets rules for how you communicate, those come first; check anything you’re unsure about with a family lawyer or mediator where you live.