The email you don't want to send

I need you to write one email for me. The email itself — not advice about how to approach it.

The situation

Marta has done our bookkeeping for six years. She is a sole trader and we are roughly 60% of her income. She has never missed a deadline, she has caught two mistakes that would have cost us real money, and I like her.

We are moving to an accounting firm that bundles bookkeeping with the audit work we now need. The decision is made, it is signed, and it is not about her work. It is also not reversible.

Her last year was hard — her husband was ill for most of it, she told me so, and twice she asked whether everything was alright with our account. Both times I said yes, and both times that was true when I said it.

I want to tell her by email. She is not someone I see in person, and a phone call I cannot schedule for another four days would be worse than a clear message today. I want her to think well of me afterwards, and I would be glad to be a reference.

The constraints

• Under 200 words for the email itself.
• She must know the arrangement is ending by the end of the first short paragraph. Do not bury it under warm-up.
• No "I hope this finds you well". No "I wanted to reach out". No "this was a difficult decision" as a stock phrase — if you say something like it, earn it.
• Do not offer future work, a reduced retainer, or "let's stay in touch about projects" unless you mean it as a commitment. I will keep whatever promise you put in my mouth.
• Give her a specific end date: 30 September.
• Do not mention her husband's illness.

Answer in exactly these sections:

The email

Subject line, then the body. Ready to send.

Why it lands where it does

Three sentences at most on the one structural choice you made — what you put first, what you left out, what you refused to soften — and what that choice costs.