How do I design a direct mail letter without a designer?

How to create an effective marketing letter that gets a reply?

Five things, on one page:

1. A headline that says what’s in it for the reader.
2. A line on why you’re writing to them.
3. One offer.
4. A reason to trust you.
5. One way to reply.

A short PS that repeats the offer gives a skimming reader a second chance to see it.

A letter has longer visibility than most advertising. JICMAIL’s Q1 2026 figures, reported by the DMA on 9 June 2026, give addressed direct mail a lifespan of 7.8 days in the home, 4.5 interactions and 141 seconds of attention per item, and 1.14 people reached by each one (DMA, JICMAIL Q1 2026 results, read 15 October 2026). That’s enough time to read one page properly, so cut anything that doesn’t serve the offer.

The same shape works for any trade. A made-to-measure curtain shop might lead with a free home measuring visit, say how long orders take to fit, and give a showroom address. A solar installer would lead with the survey, give its certification number and say plainly what the homeowner pays. What changes between trades is the detail. The order stays the same.

Does the letter need some blank space where the recipient’s address could be printed?

Yes, but only for a window envelope. There, the top of the first page belongs to the address. The recipient’s name and address are printed into a reserved area there and show through the window, so your logo, headline and wording have to stay out of it. If anything of yours is in that area, the address can print over it. With a closed-face envelope the address goes on the envelope and not on the letter itself, so the whole page is available for content.

Most UK direct mail suppliers require a clear margin around every edge, because printers leave a thin white border and anything right at the edge can be cut off or shrunk. Also, try to keep the letter to one sheet to save costs: a second sheet adds print cost and can change the envelope the letter needs. In an EcoBrace direct mail campaign, you pick the type of envelope to use: window or plain. With a window envelope, the address always prints on the first document in the pack.

How to format the marketing letter to make it easily readable?

Plainly. RNIB’s clear print guidance says body text “should ideally be 14pt and no smaller than 12pt”, in Arial or another plain sans serif font, left-aligned rather than justified. It also advises against italics, underlining and large blocks of capitals, and asks for contrast between text and background that is “as high as possible” (RNIB, Clear print guidance, read 15 October 2026). It’s written for readers with sight loss, and the same rules make any letter easier to read.

Good design on a letter is a few consistent choices: your logo at the top, one brand colour used for the headline and the reply panel, and plenty of white space. If you print in black and white, check your colour that way too: a pale brand colour that looks fine on screen can turn to unreadable grey.

What can’t a marketing letter claim?

Anything you can’t prove. The UK advertising code (the CAP Code) puts the duty on the sender. Rule 3.7 says you must “hold documentary evidence” for claims a reader would take as objective, and rule 3.9 says a letter must not mislead “by omitting significant limitations and qualifications” (CAP Code section 3, read 15 October 2026). A savings figure, a years-in-business claim or “the best-rated in the county” each needs something behind it.

Three more rules trip up small businesses. Rule 3.23 bars calling anything “free” if the reader pays more than the unavoidable cost of responding, so a free survey must be free with no strings. Rule 3.30 bars falsely saying an offer is “available only for a limited time”, so a deadline has to be real. And rule 2.1 says marketing “must be obviously identifiable as such” (CAP Code section 2, read 15 October 2026), so a letter dressed as an official or government notice is out. If you mention a grant, our heat pump direct-mail guide shows how to qualify it properly.

Post is outside the electronic-marketing rules: the ICO says “Direct marketing by post is not covered by PECR”, though you must still comply with data protection law if you use personal information (ICO, Plan direct marketing, read 15 October 2026).

Should the direct mail marketing letter have a QR code?

Yes, if you take enquiries online, as long as it’s one code that goes to a page that matches the letter. Put it beside the reply panel with a few words saying what happens when they scan it, such as “Book your free measuring visit”, and print the web address and a phone number next to it for readers who won’t scan. Test the printed proof with your own phone before you send.

Keep it simple. A single code for the whole campaign can’t tell you which home replied, so if you want to measure the campaign, send it to a page you use only for this mailing, or quote a reply code readers can mention when they call.

How does EcoBrace help you design and send the letter?

EcoBrace’s Letter builder designs the layout and also writes the letter for your Direct Mail campaign, so you go from searching for prospective customers on EcoBrace to designing and posting letters without a designer or a PDF of your own. On the campaign’s Documents step you choose Create a letter for me and answer a few questions: what you sell, your offer, how people should reply, the tone, and your contact details. You can start from your website instead, and EcoBrace pulls your logo and suggests answers from it for you to confirm. It then asks a few quick follow-up questions about your trade so it can write strong copy.

The wording is written by AI from your answers only. The page layout is fixed and print-safe: it keeps the address area clear for a window envelope or uses the full page for a closed-face one, places your logo and one QR code to your website, uses your brand colour and a choice of plain fonts, and keeps everything on one A4 sheet. The preview shows the letter as it will print, in black and white if that’s what you chose. You can edit any part of the wording, ask for one section to be rewritten (shorter, friendlier, more direct), or start again and go back to an earlier version.

Before you can approve it, the letter is checked for claims the advertising code would catch, such as “free” with conditions attached, and any figure in the letter that isn’t in your answers is flagged until you remove it or add it to your answers. Approve it, and it becomes the first document in your campaign’s pack. You then get the same free proof with real addresses as any other campaign, and you’re charged only when you send.

The limits, in the same place: every recipient gets the same letter, with no mail-merge. There’s one layout per envelope type, with no free-form design canvas. Letters made with the Letter builder are printed and posted through your EcoBrace campaign and can’t be downloaded as a PDF. Recipients come from an EcoBrace property search. You can still upload your own finished PDF if you have one. If you’d rather we helped with the letter, the list and the timing, Scout is the guided version of Direct Mail.

What does this guide not cover?

It isn’t legal advice. The CAP Code sections and the ICO guidance linked above are the rules themselves, and the advertising code’s responsibility stays with you as the sender, whoever writes the words. The guide also gives no response rate for a well-designed letter and no cost per letter. There’s no honest published response figure for your trade, and EcoBrace shows the price for your exact list before you commit.

Where do I start designing letters in EcoBrace?

Write down your offer and the one way you want people to reply, then sign up, run a search for the homes you want to reach and start a campaign from the results. If you’d like to talk it through first, contact us at hello@ecobrace.co.uk.