How Long Does a Bespoke ERP Take to Build in the UK?

Bespoke ERP timelines: what suppliers say on their own pages

Every figure below was checked on the supplier’s own page on 3 November 2026. Where a supplier does not publish a fact, the cell says so rather than guessing.

Read the time column with care. The quickest claims cover the narrowest scope. A one-day Business Central start covers a standard finance core, and “weeks” for Katana covers setting up a packaged product. A bespoke build that matches your own order, stock or production flow is a different job.

UK timelines by scope

Scope is the biggest single driver. These bands describe the shape of the work. They are not quotes.

A phased build gets the first area working early, while the next one is built. A big-bang replacement holds everything back until the whole system is ready.

A hypothetical three-area build

This example is hypothetical and uses OpsMavix’s published “from” prices and timings. It assumes the three areas are built one after another.

At the “from” prices, that is £4,950 + £2,500 + £2,500 = £9,950, with half (£4,975) paid to start. Stock control would be in use from around day 35, and all three areas from around day 95, a little over three months. Your own price and dates depend on the scope agreed in the fixed plan.

What makes a bespoke ERP take longer

The build itself is rarely the slowest part. These are the things that usually move the date:

• Unclear scope. Every “can it also…” request adds design, build and testing time. Agree the first area in writing and park the rest for later stages.
• Messy data. Duplicate products, old customer records and stock figures nobody trusts all need cleaning before migration. That is your team’s work, and it often takes longer than expected.
• Integrations. Each connection to Xero, Shopify, a carrier or an EDI partner needs mapping and testing, including what happens when a message fails.
• Slow sign-offs. Builds run on checkpoints. If the person who approves them is away or busy, the project waits.
• Bad timing. Going live in the middle of a VAT quarter, at year end or in your peak season adds risk. Our ERP implementation UK guide covers how to time go-live around VAT and payroll dates.

How to get a realistic date before you sign

1. Ask what “live” means. Is it one workflow in daily use, or the whole system? Get the answer in writing.
2. Ask for checkpoints with dates. A plan that only shows a go-live date gives you no early warning of slippage.
3. Split the work between both sides. Data cleaning, test scripts and user availability belong in the plan as named tasks with owners.
4. Check what a delay costs. On a fixed price, find out who pays if scope or dates move. On a time-and-materials quote, delay is usually your cost.
5. Compare like with like. A “live in a day” package and a bespoke build cover different scopes. Our cheapest ERP for a 20-person UK business compares the cost side the same way.

Where OpsMavix fits

OpsMavix builds owned operations systems and bespoke ERP for UK SMEs in wholesale, distribution, ecommerce and manufacturing. The homepage states:

• Fixed price in writing before the build: one area from £4,950, further areas from £2,500, the whole operation from £25,000.
• Payment: “Pay half to start, half only when it’s working.”
• Timing: a free call, a fixed plan in 5 days, then “live in 30 days” per area, built “in checkpoints you sign off”.
• Ownership: “You own the code, data and hosting”, with “no lock-in, no per-seat fees, no hostage data.”
• Integrations: works with Shopify, Xero, QuickBooks, Stripe, WooCommerce and Sage, with exactly what connects “mapped on the call, before anything is promised.”

It fits a business whose process doesn’t match a packaged product, or one that wants to stop paying per user. It is not the right choice if an off-the-shelf tool already does the job well. In that case, configure what fits. For specific areas, see wholesale order management, production tracking and inventory automation. For the cost and ownership side, read bespoke ERP software in the UK.

Frequently asked questions

How long does a bespoke ERP take in the UK?

From about a month for a single workflow to a year or more for a full replacement. MRPeasy, for example, describes its own implementations as taking “from a month to a year”. OpsMavix publishes 30 days per area, built in stages.

Can a custom ERP be live in 30 days?

One area can, if the scope is agreed up front and the data is ready. OpsMavix states “live in 30 days” per area after a fixed plan in 5 days. A whole operation is built area by area, so it takes longer in total.

Is a bespoke ERP slower than off-the-shelf software?

Not always. Setting up a packaged tool can be quick when your process matches it. When it doesn’t, configuration, workarounds and add-ons can take longer than building the workflow you need. Compare the time to get your process working, not the time to open an account.

What delays an ERP project most?

Unclear scope, data that needs cleaning, integrations and slow sign-offs. Most of these sit on the buyer’s side, so put them in the plan with named owners.

Should we build the whole ERP at once or in phases?

For most SMEs, phases. The first area is in daily use while the next is built, and each stage is tested on real work. A single big-bang go-live puts all the risk on one date.

When is the best time to go live?

At the start of a VAT period, away from payroll dates, year end and your busiest season. If that clashes with the build plan, move the go-live date rather than the testing.