A blank document is open, a decision has been made, and eight people need to know about it. Memo or email? Most of us default to email without thinking, then wonder why nobody read past the second line. The format you choose shapes how seriously your message is taken, how long it survives, and whether anyone can find it when a question comes up in six months. Here is how to choose deliberately.
Speed: Where Each Format Earns Its Place
Email wins on the send button. A message to a colleague takes ninety seconds and gets answered before the kettle boils. But speed of sending is not the same as speed of understanding. A short email about a change to the expenses process often produces three replies, two of which ask the same question.
Memos are slower to write, and that is the point. A memo asks you to state who it is for, what has changed, why, and what happens next. Ten minutes of drafting saves a fortnight of clarification. Use email when you need an answer today. Use a memo when you need twenty people to understand the same thing in the same way, and to still understand it next month.
Formality: Reading the Room Before You Write
Memos signal that something is settled. Emails suggest a conversation is still open. Announce a new hybrid-working policy by email and it reads as a proposal; send the same words as a memo on letterhead and it reads as a decision. That difference matters when you are changing hours, introducing a process or confirming a restructure.
Tone differs too. Memos are usually impersonal and third person — “the team will move to…” — because they speak for the organisation rather than the person typing. Emails can carry warmth, humour and a first name. Neither is better; they do different jobs.
Pay attention to your own workplace before you decide. Some UK organisations have not used the word “memo” in years, and the formality lives in a well-structured email with a precise subject line. In universities, NHS trusts, councils and larger firms, a memo still carries weight and may even be expected. Watch what senior colleagues do, and follow the house style rather than fighting it.
Record-Keeping and Accountability
Emails live in inboxes, which are fragile archives. People leave, mailboxes are closed, threads split into three versions, and the decision ends up in whichever copy the recipient happened to keep. A memo circulated as a single document — filed on the shared drive, attached to the project folder, pinned to the staff noticeboard — is far easier to retrieve and cite later.
A memo also dates itself. The header tells you who wrote it, when, and to whom it went. If a question arises about what was agreed, that is the document you want to be holding. Most organisations have a retention policy covering business records, so check yours before deleting anything relating to contracts, safety, disciplinary matters or finances. If a dispute looks likely, take proper advice on what to keep rather than deciding alone.
Choosing Between Them: Common Scenarios
When you are unsure, the scenario usually makes the decision for you.
Use a memo for:
- Policy, procedure or deadline changes affecting a whole team or department
- Restructures, new reporting lines, office moves and staffing announcements
- Formal briefings that will sit in a project file, board pack or audit trail
- Anything where you need to show that everyone received identical wording on a specific date
Use email for:
- Scheduling, confirming, chasing, and quick questions to one or two people
- Conversations with clients, suppliers and anyone outside the organisation
- Threads that genuinely need back-and-forth discussion
- Follow-ups that summarise what was agreed in a meeting
You can also use both. Send the memo as a PDF attachment with a two-line covering email saying what it is and what you need people to do. That pairing gives you the formality of the memo and the reach of email.
Writing Each One Well
Memos
Keep to a predictable shape: To, From, Date and Subject at the top, then a one-sentence purpose such as “This memo confirms the new booking process for pool cars, effective 1 May.” Follow with short numbered sections and finish with a clear action line — who does what, by when. Write in plain English and cut the adjectives. A memo that hedges reads as though nobody has decided anything.
Emails
Make the subject line do work: “Action needed: confirm March rota by Friday” beats “Rota”. Put the ask in the first two lines, before the background. Keep one topic per email, and if you need three answers, number them so nobody replies to only the easy one. Long threads are for discussion, not for announcements.
The worst option is a hybrid: a 900-word email with no headings and a vague subject line, or a memo so chatty that nobody realises it is a decision. Pick one form and commit to it.
The Practical Rule
Ask three questions before you start typing.
- Will someone need to find this in six months? If yes, write a memo — or write the email and save it as a document in the right folder.
- Is this a decision or a discussion? Decisions become memos. Discussions stay as email until they settle, and then a short memo records the outcome.
- Who needs it, and do they all need the same words? One or two people: email. A whole team, all at once: memo.
A memo is not automatically more professional, and an email is not automatically lazy. The right choice is the one that gets read, understood and found again. Match the format to the lifespan of the message, keep it short, and you will spend far less time explaining what you meant.
Photo: markusspiske / Pixabay
