Too small and it will not do what you need. Too big and you are paying for things you will never use. Just right has to scale with you. A plain-English guide to the three tiers of business software, where Xero, Sage, Business Central and the big suites sit, and how to tell which one is the right size for your business.
Goldilocks tried three bowls of porridge. The first was too hot, the second too cold, the third just right. She did the same with the chairs and the beds. It is a children's story, and it is also the best model I know for choosing business software, because the two ways to get it wrong are opposites, and most companies only worry about one of them.
Buy something too small and it will not do what you need. You will know within a year: spreadsheets grow around it, people re-key, and the month-end takes longer every quarter. Buy something too big and you will pay, every month, for depth you never use, and you will pay again in the implementation, because big software assumes a big team to run it. The second mistake is quieter than the first, so it gets made more often than people admit.
A note on bias before we start: we implement Microsoft Dynamics 365 Business Central, which sits in the middle tier below, so we are not neutral. We will say where it is the wrong answer. But we will also say, because it is true, that it is a tier 2 product that is quickly competing with tier 1 on functionality, and that changes where the "just right" line falls for a lot of businesses.
The industry talks about "tiers" of ERP. The boundaries are fuzzy and the vendors argue about them, but the shape is consistent.
Examples: Xero, Sage 50, QuickBooks, FreeAgent, Sage Business Cloud Accounting.
These are bookkeeping systems with some invoicing and stock bolted on. They are cheap, fast to set up, your accountant already knows them, and for a business with one entity, simple stock (or none), and a handful of users, they are the right answer. Do not let anyone talk you out of Xero if Xero is doing the job.
Where they run out: multiple companies with intercompany, anything beyond simple stock (lots, serials, bins, assembly, manufacturing), multi-currency at any real volume, approval workflows, dimensions-based reporting, proper purchase ordering, and integration with anything other than a bank feed and a web shop. The usual tell is a growing forest of spreadsheets doing the things the system cannot, and one person who is the only one who understands them.
Examples: Microsoft Dynamics 365 Business Central, Sage Intacct, Sage 200, NetSuite, SAP Business One, Acumatica.
These are full ERPs: finance, sales, purchasing, stock, warehousing, manufacturing, projects, service, all on one database with one chart of accounts and one set of dimensions. Multi-company, multi-currency and intercompany are standard. They integrate properly (APIs, not CSV exports), they have an ecosystem of add-ons for industry needs, and they can be configured by a small team rather than an army.
The spread within the tier is wide. Sage 200 and SAP Business One are the traditional on-premise or hosted end; Business Central, Intacct, NetSuite and Acumatica are cloud-first. Intacct is strongest in pure finance and multi-entity services businesses; NetSuite and Business Central cover operations (stock, manufacturing, warehousing) as well as finance. Business Central is priced per user per month on public UK list prices, with the price depending on whether a user needs the Essentials or Premium (manufacturing and service) edition, and it sits inside Microsoft 365, Power BI and Copilot, which matters if that is already how your business works.
Here is the bias, stated plainly. Business Central is the tier 2 product that has moved furthest up the scale. Ten years ago as Dynamics NAV it was a solid mid-market system. Today it has full manufacturing (production orders, routings, capacity, subcontracting), directed put-away and pick warehousing, intercompany and consolidation across any number of companies and countries, project accounting, service management, AI agents for payables and sales orders, and two major releases a year from Microsoft with the same engineering investment as the tier 1 products. It now does things that five years ago would have sent you to a tier 1 suite. It is still a tier 2 product in price, in implementation effort and in the size of team it needs to run, which is exactly the point: tier 1 depth in the places that matter, without the tier 1 weight.
Where they run out: very high transaction volumes across many countries, deep statutory localisation in dozens of jurisdictions, global shared service centres, and process-heavy industries (large-scale process manufacturing, utilities, complex multi-site retail) that need the depth of a tier 1 suite. If you have a 200-person finance function, you are probably past this tier.
Examples: SAP S/4HANA, Oracle Fusion Cloud ERP, Microsoft Dynamics 365 Finance and Supply Chain Management, Workday Financials, Infor (for some industries).
These are built for large, complex, often global organisations: thousands of users, dozens of legal entities and countries, industry-specific depth that goes very deep indeed. They are enormously capable, and they assume an organisation with the money, the governance and the in-house team to match. Implementations are measured in years and seven or eight figures, and the big-name failures you read about in the companion piece on why ERP projects fail are almost all tier 1 projects that organisations were not ready for.
Where they go wrong for the wrong buyer: a 150-person manufacturer buying a tier 1 suite gets a product designed for a 15,000-person one. Every screen has forty fields they will never use, every process has approval layers they do not need, and every change needs a specialist they do not employ. They pay for all of it. They do not get a better system; they get a heavier one.
Goldilocks did not read the label on the porridge. She tasted it. Here are the tastes.
Goldilocks tested three things, and so should you. The porridge is functionality: does it do what the business does? The chair is cost and fit: can you sit in it comfortably, every month, with the team you have? The bed is scalability: will it still fit when you have grown, and will the vendor still be investing in it? A system can pass one test and fail another. Plenty of tier 1 porridge is delicious and the chair collapses under the licence bill. Plenty of tier 3 porridge is fine until the bed turns out to be a cot.
Getting the porridge right today is not enough. An ERP project is expensive and disruptive, and if the product only fits for a couple of years you have paid all of that for very little. The real test of "just right" is whether the product scales with the business: more users, more companies, more countries, more volume, and, hardest of all, different processes as the business changes shape. The company that buys at £8m turnover with one warehouse needs the same product to be comfortable at £40m with three, a manufacturing line and an acquisition, without a re-implementation.
That is the honest case against tier 3 for a growing business: the ceiling is low and you hit it fast. It is also the honest case against buying tier 1 too early: you are paying now for scale you may reach in ten years, if ever, and the cost of running it meanwhile slows down the growth it was supposed to support.
It is also where the Business Central argument is strongest. It starts small (a handful of users, one company, standard finance) and the same product, with no migration, runs multi-company, multi-country, manufacturing and warehousing at hundreds of users. The ceiling is high, Microsoft keeps raising it twice a year, and when a business finally does outgrow it, the move to Dynamics 365 Finance and Supply Chain is a move within the same family, same data model, same Microsoft stack, rather than a rip and replace. Every business that grows far enough will eventually have to change software. The aim is to make that once, late, and planned, not every few years by accident.
As a rough guide, and with every caveat about industry and complexity:
| Business | Usually the right bowl |
|---|---|
| Up to about 10 users, one company, simple or no stock | Tier 3: Xero, Sage 50, QuickBooks |
| 10 to 300 users, one to twenty companies, real stock, warehousing or manufacturing, integrations | Tier 2: Business Central, Intacct, NetSuite, Sage 200, SAP Business One |
| Multi-entity services business, finance-led, little or no stock | Tier 2, finance-strong: Intacct or Business Central Essentials |
| Hundreds of users, many countries, deep industry process, large in-house IT and finance teams | Tier 1: S/4HANA, Oracle Fusion, D365 Finance and Supply Chain. Business Central reaches further into this row every release |
The middle row is where most UK businesses between about £5m and £250m turnover sit, and it is the row that gets the Goldilocks mistake in both directions: stretched on Sage 50 long after it hurt, or sold a tier 1 suite by a partner who needed the revenue.
This is the move we see most, and the one businesses put off longest, because the current system is cheap and familiar and the pain arrives slowly. The signs above are the trigger. The good news is that it is a well-trodden path: Xero, Sage 50 and QuickBooks all migrate cleanly into Business Central, and we have written up what the migration involves. If you want a number, the licensing calculator gives you the Business Central cost for your user mix in about a minute.
The right product is not the one with the most features, or the one your competitor uses, or the one the biggest partner recommended. It is the one that does what your business does, in standard, with a team you can afford, and that will still be doing it in five years when the business is twice the size and does things differently. If you are not sure which bowl is yours, that is a thirty-minute conversation, not a sales cycle. Book a call and we will tell you honestly, including if the answer is "stay on Xero".
