Choosing envelopes for school letters and documents
Choose an envelope around what it must carry and how the recipient will open and read it. Test the finished letter, any inserts and the address position before producing a large batch for families or other organisations.
Fit the contents without forcing them
Make a sample with all the intended inserts, not just the main letter. A consent form, return slip and information leaflet can change the thickness of the pack. Decide whether folding is acceptable or whether a document needs to remain flat. Check that corners slide in easily and that the flap closes without pulling the envelope out of shape.
For a window envelope, move the contents gently in several directions and check the visible address throughout. Information above or below the address should not drift into the window. A different printer margin or a revised letterhead can change alignment even when the envelope has not changed.
Produce a clear outward-facing pack
Use an address source that has been checked through the school's normal process. Make the text readable and keep additional identifiers off the exterior unless they are necessary for the task. A return address can help with undeliverable mail, but it should be the school's agreed address rather than a staff member's personal detail.
Compare the sealing method through a short packing trial. Consider ease of opening, the time needed to prepare a batch and whether stored envelopes still seal as intended. Keep envelopes flat and away from conditions that could affect the adhesive. Do not assume an old box remains suitable simply because it is unopened.
Check the completed mail piece
Weigh and measure a finished pack when postage classification matters, using the carrier's current rules. Include every insert and the envelope itself. A change to a booklet, folder or protective insert can affect the finished item, so repeat the check when the contents change.
For an important mailing, approve one complete sample and keep it beside the packing area. Check a small selection during the run for missing inserts, address alignment and closure. Plan how returned or incorrectly addressed mail will be investigated without leaving confidential correspondence in an open general tray.
Action checklist
- Test the complete set of inserts.
- Check window alignment with normal movement.
- Confirm the agreed address source.
- Measure a finished pack before calculating postage.
Common questions
Can the same window envelope be used with a new letter template?
Test it first. Revised margins, fonts or letterheads can move the address or expose other text, even when the envelope and paper sizes are unchanged.
Sources and scope
Source titles are provided for reference. Check the current original guidance and your school's circumstances before making a policy or compliance decision.
- Schools Direct editorial — Original school office resource planning guidance and worked examples. Checked 1 November 2026.