Is custom ERP more expensive than off-the-shelf ERP?

Up front, yes. Over five years it depends on users and customisation. Package licences are charged per user every month, while a custom system you own has no licence fees. For many users, or processes a package can only handle with heavy customisation, custom ERP is often cheaper over five years.

How long does custom ERP take compared with off-the-shelf?

A focused custom module, such as stock or production, typically takes 8 to 12 weeks from first meeting to launch, and a full ERP with several integrations 4 to 6 months. Off-the-shelf can be faster when the package fits without customisation, and slower when it does not.

Can we start with off-the-shelf ERP and move to custom later?

Yes. Many businesses keep their accounting package and replace only the parts that no longer fit, with integration keeping the two in step. Moving later is easier if you keep your data exportable and avoid deep customisation of the package in the meantime.

Can a custom ERP work alongside Sage or Xero?

Yes. Custom ERP is often built to handle operations such as production, ordering or stock, while invoices and payments sync automatically to Sage, Xero or QuickBooks, so the finance team keeps the package it knows.

Custom ERP vs Off-the-Shelf: Cost, Fit and Risk

How do custom and off-the-shelf ERP compare?

Factor	Off-the-shelf ERP	Custom ERP
Up-front cost	Lower: configuration, data migration and training	Higher: discovery, build, data migration and training
Running cost	Per-user subscription that rises with headcount	Hosting and support, flat as users are added
Time to first use	Weeks to months, depending on configuration	8 to 12 weeks for a focused module; 4 to 6 months for a full ERP
Fit to your processes	You adapt to the package	Built around how you already work
Customisation	Limited, charged separately, and can break on upgrade	Part of the system, changed when you choose
Upgrades	On the vendor's schedule	On yours
Ownership	A licence to use; the vendor owns the code	You own the system and its intellectual property
Integrations	The vendor's connector catalogue	Built to your systems, such as Sage, Xero, QuickBooks or SAP
Supplier risk	Price rises, product changes or end of life	Standard Laravel code any competent developer can maintain

How do they compare on cost over five years?

Compare total cost over five years, not the first-year quote. These are the lines to fill in for each option:

Cost line	Off-the-shelf ERP	Custom ERP
Software	Licence per user per month × users × 60 months	None: you own it
Implementation	Configuration, data migration and training	Discovery, build, data migration and training
Customisation	Partner day rates for anything outside the standard package	Included in the build
Hosting	Usually inside the subscription	Monthly hosting × 60 months, or your own infrastructure
Support and change	Support tier or partner retainer, plus upgrade projects	Support retainer, plus changes as small fixed-price projects

The deciding variable is usually headcount. Licence costs grow with every user; a custom system's running cost does not. A business with a few users and standard processes will usually spend less on a package. One with many users, or with processes a package can only handle through heavy customisation, often spends less on custom ERP over five years. We give a fixed-price quote after a discovery conversation, so the custom column can be filled in with real numbers.

When is off-the-shelf ERP the right answer?

Your processes are standard for your sector, and the package handles them without customisation.
You have a small number of users, and that is unlikely to grow much.
You need to be live in weeks rather than months.
You would rather follow a vendor's product roadmap than set your own.

If that describes you, buy the package. We will say so in the first conversation.

When is custom ERP the right answer?

The way you work is part of your advantage, such as made-to-measure ordering, which the OS Doors trade portal handles alongside stock items.
The customisation quote for a package is approaching the cost of building what you need.
Per-user fees are growing faster than the business.
You run several sites or regions with different rules, as Trade Mouldings does across Northern Ireland, the Republic of Ireland and Great Britain.
The package does not connect to systems you depend on.

Is there a middle path?

Often, yes. Many businesses keep an accounting package that works, such as Sage or Xero, and build only the part no package handles well: production, ordering or field operations. The custom part is then smaller, and the two are kept in step by integration rather than replaced.

Checklist: deciding between custom and off-the-shelf ERP

List the processes a package would make you change, and decide which of them matter.
Count users now and in five years, and price the licences for both numbers.
Ask the package partner for a written quote for the customisation you need.
List every system the ERP must connect to, and check each one is supported.
Decide who in your business will own the system day to day.
Ask what happens if the vendor raises prices, or if you part company with the developer.

For what a custom build involves, see our custom ERP software service.

Tell us what's broken. We'll tell you what it takes to fix it.

Describe it in a few sentences. We'll come back within one working day, and you'll be speaking to the engineer who would build it, not a sales team.

Custom ERP vs off-the-shelf ERP