How to send letters in bulk: 5 key steps to know

Reaching thousands of people at once doesn’t have to be slow or expensive. Bulk mailing services let businesses, charities and other organisations send large volumes of letters at a fraction of the usual postage cost, making it a powerful way to promote, fundraise and stay in touch. It works because volume unlocks significant discounts. If you’ve never run a campaign like this before, there are a few essential elements to understand before you start.

What counts as bulk mail?

The first thing you need to do – even before you start collecting data and drafting your content – is make sure your campaign will meet the minimum volume requirements. To access sorted bulk mail discounts, you need to send at least 1,000 Large Letters or 4,000 Standard Letters in a single mailing. Anything below these thresholds can still be posted, but won’t attract the discounted rates that make bulk mailing so cost-effective.

There’s no upper limit, so the larger your campaign, the more you stand to save per item. Once you know your mailing qualifies, the process breaks down into five clear steps.

Step 1: Prepare and clean your data

Clean data is the foundation of a good campaign. Start by removing duplicates and correcting errors or partial addresses, so you aren’t paying to print and post items that will never arrive. Just as important is screening your list against suppression files, removing gone-aways, deceased records and people registered with the Mailing Preference Service.

This keeps your mailing accurate, protects your budget and helps you reach genuine, contactable recipients. Effective data cleansing means fewer returns, less waste and a campaign that lands with real people.

Step 2: Choose your format

Letters are among the most common use cases for bulk mail, but you don’t have to limit yourself to this format. Leaflets, flyers, postcards, brochures, newsletters and catalogues can all qualify, giving you plenty of ways to reach your audience.

What you choose directly affects the price. For letters, mail is split into two formats, based on size and weight, as follows:

Standard Letters: Up to 240mm x 165mm x 5mm and a maximum weight of 100g.
Large Letters: Up to 353mm x 250mm x 25mm and 750g.

Anything above Large Letter limits moves into pricier parcel rates, or Publishing Mail services for certain magazines and periodicals. Packaging matters too, as an outer envelope or wrap adds to the weight and thickness that determines your postage cost.

Step 3: Select postage class and identify discount requirements

Your postage class sets the balance between cost and speed. First Class aims for next-day delivery at a higher price, while Second Class and Economy options cost less but take longer, which is fine for most non-urgent campaigns. Class alone, though, isn’t what unlocks the biggest savings.

To access bulk discounts, your mail needs to meet specific Royal Mail requirements. For example, pre-sorting groups your mail by destination so less handling is needed, while Mailmark® adds a barcode that lets Royal Mail process each item automatically. To qualify for Mailmark, your mail must use complete, accurate addresses with valid postcodes.

Step 4: Personalisation, print and fulfilment

Even at high volume, your mail doesn’t have to feel generic. Variable data printing tailors each item to its recipient, changing names, addresses, images and offers across thousands of pieces in a single run. For printing, digital suits shorter runs and heavy personalisation, while litho is cost-effective at scale. Your choice depends on volume and finish.

Fulfilment then brings it together, from folding and enclosing to polywrapping for bulkier packs. A good mailing house handles all of this in one place, managing print, personalisation and fulfilment together so your campaign stays consistent, accurate and on schedule from start to finish.

Step 5: Dispatch and tracking

Once your mail is printed, sorted and prepared, it’s handed to your postal provider to enter the delivery network. Dispatch isn’t the end of the story, though. Tracking how a campaign performs lets you prove its value and improve the next one.

At scale, Mailmark enables reporting on processing and expected delivery dates across the campaign as batches of items move through the postal network. Within mail itself, including response tools such as QR codes, personalised URLs and unique vouchers helps to show mail’s impact on enquiries and sales.

How much does it cost to send letters in bulk?

The cost of a bulk mailing is shaped by several factors working together, so actual prices can vary significantly. Your volume, the format, size and weight of each item, your chosen postage class and how your data is sorted and Mailmarked all feed into the final rate. That’s why two campaigns of the same size can be priced very differently.

The best way to understand what your campaign will cost is to talk it through. Get in touch with The Mailing People to discuss your options and get a tailored quote for your mailing.

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Frequently Asked Questions

Yes. A franking machine is only one way to pay for postage, so you don’t need one. The simplest option is to use a mailing house, which handles everything for you.

No. If you use a mailing house, they take care of all the postage arrangements for you, so there’s nothing you need to set up or apply for yourself.

It depends on the service you choose, ranging from next working day for First Class to around six working days for Economy. Allow a few extra days for your mail to be produced first.

You need at least 1,000 Large Letters or 4,000 Standard Letters in one mailing to qualify for bulk discounts. There’s no maximum, and larger mailings usually cost less per item.

They can cleanse your data, print and personalise letters, then sort and prepare everything to qualify for discounts. Your mail is then passed to the postal provider and sent out.

Send in high volume, keep items small and light, and choose a slower delivery speed. The biggest savings come from using a mailing house, which unlocks discounted rates you can’t access on your own.