A B2B prospecting letter is a short, addressed letter sent to a named decision maker at a company you want as a customer. Its job is to earn a reply or a meeting, not to close a sale, so it should make one relevant point and ask for one small next step.
Overview
Prospecting by post works because it is uncommon. A decision maker who deletes cold emails unread may still open a letter that carries their name and a point clearly about their business. The letter then gives your sales team a reason to call: “I wrote to you last week about…”.
The strongest prospecting letters are researched, not mass-produced. Even a single line that shows you know the company, such as a recent expansion, a new site or a regulatory change in their sector, signals that the letter was meant for them.
Think of the letter as the first touch in a short sequence: letter, then phone call, then email, then a second letter if appropriate. Plan the whole sequence before you post anything.
When to use it
How to start, step by step
- Build a short target list. Start with accounts that match your best existing customers. A few hundred well-chosen contacts usually beat thousands of loose ones.
- Confirm the right person and a lawful basis. Identify the role who owns the problem, use business contact data you can justify under UK GDPR, and record its source.
- Write a relevance line per segment. Group accounts by sector or trigger event and write an opening line for each group so every letter feels specific.
- Ask for something small. A 15-minute call, a short audit or a sample is easier to agree to than a sales meeting.
- Schedule the follow-up. Book calls for a few working days after posting and give the sales team a copy of each letter version.
Which format to choose
| Use | Format | Why | From, per item |
|---|---|---|---|
| First-touch prospecting letter | Letter — A4 | Personal and formal; easy to pass to a colleague. | £1.90 |
| Event or webinar invitation to prospects | Postcard — A5 landscape | Short, visual and seen without opening. | £2.20 |
| Second touch to engaged accounts | Postcard — A5 enveloped | Enveloped, so it feels considered without a full letter. | £2.20 |
Prices come from the live AutoLetters price list. They include printing and UK postage, are the same at any quantity, and have no VAT added because AutoLetters is not VAT registered.
Worked example
Illustrative scenario, not a customer case study. A commercial cleaning firm writes to facilities managers at 200 offices in its region offering a free site walk-round. Letters are grouped by building type with a different opening line for each, and calls follow a week later.
200 × Letter — A4 at £1.90 each = £380.00, printed and posted.
Response depends on your list, offer and timing, so we do not quote response rates. Measure your own with a unique code or web address.
Mistakes to avoid
- Addressing letters to a job title rather than a person.
- Asking for a full sales meeting in the first letter.
- Sending letters with no sales follow-up, so interest goes cold.
- Using the same generic copy for every sector.
Preparing artwork that prints correctly
Every format has a trim size, a bleed area and a safe zone. Extend background colours and images into the bleed so no white edge appears after cutting, and keep text, logos and QR codes inside the safe zone. Use images at 300 DPI at printed size, and leave the address area clear, because the printer adds the recipient's address there. Each product page lists the exact supplier measurements, and Lenny checks uploaded artwork against them before you approve it.
Building a list you can use
You can send to a list you already hold or to an audience of UK addresses built around a postcode. If you use your own list, include only people you have a lawful basis to contact by post, remove anyone who has asked not to hear from you, and keep a record of where the data came from. The Information Commissioner's Office publishes guidance on direct marketing under UK GDPR. Check that every address is complete and current: incomplete addresses cost money and do not arrive.
Measuring the result
Decide how you will count responses before you send. A unique discount code, a short web address, a dedicated phone number or a simple “how did you hear about us?” question all work. Divide the campaign cost by the number of responses to get a cost per response, then compare it with your other marketing. Where you can, hold back a small group from the mailing, so you can see how many of them would have responded anyway.
How AutoLetters handles it
Lenny, the AutoLetters AI campaign specialist, helps you choose a format, drafts the wording and artwork to the printer's exact measurements, and helps build the audience: either UK addresses around a postcode or a list you already hold. You review a print-accurate preview, then approve the exact print file. Nothing is printed or posted until you approve it.
AutoLetters sends addressed mail to UK addresses only and does not offer unaddressed door drops. Postal delivery timings are not guaranteed.
Questions
Is it legal to send prospecting letters to businesses?
Postal marketing to named business contacts is generally possible under UK GDPR on the basis of legitimate interests, provided you assess it, tell people how you use their data and honour objections. The ICO publishes guidance on this.
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