How we compare email marketing software
We list 15 email platforms sold to UK businesses, and a published rate card exists for 14 providers. Where a vendor quotes rather than publishes, we show the quote instead of inventing a figure, because a number attached to a company that refuses to print one is a guess wearing a price tag.
The calculator takes two numbers, not one: how many subscribers you hold and how many emails you send in a month. That is deliberate. A platform that charges for stored contacts and one that charges for sends rank in opposite orders depending on which of those two numbers is large, so a table driven by list size alone would quietly favour half the market.
There is a third input for whether you need automation, because on much of this list automation is the thing that moves you off the entry plan rather than list size.
Ranking is arithmetic on published rates at the numbers you enter. Commission never moves a provider, we do not sell position, and prices are what each vendor publishes to a UK buyer. Some of those are monthly prices and some are the monthly equivalent of an annual commitment, so read the billing basis alongside the figure.
Dotdigital, EmailOctopus and Transpond: the British end of email marketing software
This is one of the few categories on this site where a UK buyer has genuinely domestic options, and it is worth knowing what that does and does not buy you.
Dotdigital lists its origin as United Kingdom and sits at the quoted end of the market: its free plan row reads No (demo / contact sales) and its contract row reads Yes, against No for most of the rest of this table. Its SMS row reads Yes (native, omnichannel), which is the practical reason a UK retailer ends up on a platform like this rather than an email-only one.
EmailOctopus lists United Kingdom and prices a real GBP rate card, opening at £9/mo (Pro). Be honest with yourself about the trade: its segmentation row reads Basic (tags, segments) and its integration count reads 20+. That is a newsletter tool that does its job cheaply, not a marketing suite.
Transpond lists United Kingdom and opens at £7.20/mo (Starter), with SMS shown as Yes (add-on, UK customers only). Its e-commerce row reads None native (Stripe, WordPress; stores via Zapier), so a shop should look elsewhere. Spreeflo also lists United Kingdom and is the newest listing here, opening at £10/mo (Starter) with its e-commerce row reading None published (REST API, webhooks and MCP server only).
What being British-built gets you is a support desk in your timezone and a contract governed by law you can enforce without crossing an ocean. What it does not get you is a feature advantage, so buying one on principle alone will cost you somewhere else on this list.
Stored contacts or emails sent: which meter your email marketing software runs on
Nearly every argument about what this category costs comes down to a single question that vendors answer differently, and almost nobody asks before signing up.
Most of the table charges for the people on your list. ActiveCampaign lists Per contact, Klaviyo Per active profile, MailerLite Per subscriber and Transpond Per active contact. On that meter, sending more often is free and adding people is what costs money.
Brevo runs the other meter: its pricing model reads Per email volume and its contact row reads Unlimited contacts (billed by sends). On that meter, holding a list costs nothing and mailing it is what costs money.
HubSpot is a third shape again, listing Per seat, so contacts decide which plan you are allowed to buy while seats decide the bill.
The consequence is concrete. A membership body with a big dormant list that mails a newsletter each quarter, and a busy shop with a short list it mails several times a week, are quoted in opposite directions by the same vendors. Neither is being overcharged. They are being measured on different axes.
So work out which of your two numbers is the awkward one before you shortlist anything. If your list is large and your sending is light, a per-send platform is the shape that fits. If you send constantly to a modest list, a per-contact platform stops punishing you for frequency. Put both real numbers into the calculator rather than the one you happen to know.
Unsubscribes, bounces and the contacts your email marketing software still bills for
Once you know which meter you are on, the next question is what the meter counts, and this is where the invoice and the law pull in opposite directions.
Some platforms bill everyone in the database. Mailchimp's contact row reads All contacts including unsubscribed, Omnisend's reads All contacts including non-subscribers and ActiveCampaign's reads All contacts (active + inactive). Others bill only the people you can actually mail: Klaviyo's reads Active profiles only (excludes suppressed), AWeber's Active subscribers (unsubscribes excluded) and MailerLite's Active subscribers.
Read that difference carefully, because it means you can be paying to store people PECR forbids you from emailing. Someone who unsubscribed is a person you must not mail again, and on the first group of platforms they still consume a paid contact slot until you remove them. So does a hard-bounced address that will never be delivered to again.
Spreeflo counts differently again, listing Peak marketing contacts in the month (non-marketing contacts and form responses unlimited and uncounted), which means a one-off import you later delete can still set the month's charge.
So list hygiene is a billing control as well as a deliverability one. Two cautions before you start deleting. First, deleting an unsubscribed record is not the same as suppressing it: if you delete the person and a later import reintroduces them, you have lost the only evidence that they opted out. Keep the suppression entry and remove the billable profile only where the platform lets you do both. Second, check what the vendor counts before assuming a purge changes anything, because on a per-send platform it will not.
Send allowances on paid email marketing software, and the free rungs below them
The assumption that trips people up on a per-contact plan is that sending is unlimited once you have paid for the contacts. It often is not. Transpond states the limit openly, listing Active contacts (fair use: 12x contacts /mo in sends), so the allowance is a multiple of the list rather than an open tap. Where a vendor does not publish a multiple, treat the ceiling as unknown rather than absent and ask before you plan a daily send.
The free tiers here are real, and they are capped on more than one axis at once, which is what makes them run out unexpectedly. Kit lists Yes (10K subscribers, 1 automation, no A/B), EmailOctopus Yes (2,500 subscribers, 10,000 emails /mo), MailerLite Yes (250 contacts, 2,500 emails /mo), Mailchimp Yes (250 contacts, 500 sends /mo) and Transpond Yes (250 contacts, 3,000 sends /mo, no automation). Brevo's free row reads Yes (300 emails /day, unlimited contacts), which is the send meter showing up again at the bottom of the ladder. Spreeflo's reads No (forms only).
Notice what those rows cap. Contacts, sends, and features, frequently all three. Automation is the usual feature gate: MailerLite lists Basic (Comfort), Advanced (Power), EmailOctopus Basic (time-based, Pro) and Mailchimp Basic (Essentials), Advanced (Standard+), so a welcome sequence and an abandoned-basket flow are what usually move a small business onto a paid rung, not list growth.
If you send one newsletter a month to a few hundred people and have no automation, you probably do not need to pay for this yet, and you should not let a comparison table talk you into it. The moment to start paying is when a specific automation is worth more to you than its plan, or when a cap starts costing you a send you needed to make.
B2B and B2C consent under PECR: what UK email marketing software cannot decide for you
Bulk marketing email to UK recipients is governed by the Privacy and Electronic Communications Regulations as well as UK GDPR, and PECR is the one that decides whether you may press send at all. This is not the same regime the software was probably designed for. US CAN-SPAM is an opt-out law where you may email a stranger provided you honour the unsubscribe. PECR is not, and a platform whose defaults were built for the American market will happily let you do something here that you should not.
The split that has no equivalent in most other markets is who the recipient is. Marketing email to an individual subscriber generally needs consent, with a narrow exception known as the soft opt-in: broadly, where you obtained the address in the course of a sale or negotiations for a sale, you are marketing your own similar products, and you gave a clear chance to refuse both at the point of collection and in every message since. Corporate subscribers, meaning incorporated bodies rather than people, are treated differently. Sole traders and unincorporated partnerships are not corporate subscribers, so a "B2B" list of small UK businesses is very often a list of individual subscribers wearing a business hat.
Separately, and regardless of who the recipient is, every marketing email needs a working unsubscribe and a sender who is identifiable rather than disguised.
A bought or scraped list is not consent. Neither is a list that arrives with a business you acquired, because consent was given to a relationship rather than attached to a file.
Every platform here carries some tooling for this: the consent row reads Yes (EU-hosted, consent tools, unsubscribe) for MailerLite, Yes (EU-hosted, consent tools, unsubscribe) for Brevo, Yes (UK company, DPA, unsubscribe, list cleaning) for Transpond, Yes (DPA on every plan, EU SCCs and UK IDTA, double opt-in; data processed in the US) for Spreeflo and Yes (consent management, subscription types, cookie banners) for HubSpot. Tooling is not compliance, though, and no vendor can be responsible for how you gathered your list.
The questions worth asking a vendor, rather than assuming: does it record the date, source and method of consent against each contact rather than just the address; does it offer double opt-in and is it on by default; can it hold separate subscription types so someone can opt out of marketing without losing a service email; and where is the data processed, under which transfer terms. For what the rules actually require of you, the ICO publishes direct marketing guidance, and anything turning on your specific list is a question for your own adviser rather than for us.
Switching email marketing software when the consent evidence has to move too
Moving platform is easy in the sense that a CSV of addresses will import anywhere, and that is exactly the trap. Addresses are the part of your list with no legal value. The part that matters is the record of how each person came to be on it.
Before you export, work out whether you can take four things with you. The consent record against each contact, including when and how it was given. The suppression list of everyone who unsubscribed or bounced. Your subscription categories, if you run more than one. And the engagement history, which is what lets you sunset dormant contacts on the new platform instead of paying to store them.
The suppression list is the one people forget, and it is the one that causes an actual complaint. If it does not migrate, your first send from the new platform goes to people who told the old one to stop, which is precisely the scenario PECR exists to prevent. Confirm that it imports before you switch, not after.
Contract shape mostly helps you here. Most of this table lists No, so you can run both platforms in parallel for a month while you check the migration rather than switching cold. Dotdigital lists Yes, which is normal at the account-managed end and worth knowing before you commit.
Last, you are changing sending infrastructure as well as software. Your authentication records need setting up for the new sender before volume moves, and reputation is built on the new platform rather than inherited. Vendors report this inconsistently: Klaviyo's deliverability row reads Very high (e-commerce specialist), ActiveCampaign's reads Very high (94% in independent tests), while Spreeflo's reads No published benchmark and Transpond's reads Not stated. Move your most engaged segment first, watch what happens, and only then move the rest.