From Duplicate Chaos to Clean Data: b4b’s Customer Merge System for Collins Nets

Every growing business collects a bit of digital clutter, but for Collins Nets, that clutter had a name: duplicate customer records. Years of orders arriving through different channels, re-entered details, and small inconsistencies had left their Sage system carrying a significant number of duplicates, the kind that build up quietly until they start slowing everything down.

The team had been tackling it the only way they could, by hand. It worked, but only just. New duplicates appeared faster than old ones could be tidied away, so the list never actually got shorter. Collins Nets needed something that could keep pace with the problem rather than constantly chasing it.

Collins Nets runs on Sage 200 for its accounting, which meant any fix had to work with that system rather than around it. The duplicates weren't always obvious either. Some were near-identical records with a typo in the surname; others were the same customer using slightly different contact details across separate orders.

Manually reviewing and merging records is fine at small volumes, but it doesn't scale. Every hour spent tidying data is an hour not spent serving customers, and the risk of human error only grows the more records there are to check. What Collins Nets needed was a system with enough intelligence to spot genuine duplicates on its own, but enough caution not to merge anything it wasn't sure about.

b4b's development team built an automated duplicate detection and merge system that connects directly to Collins Nets' Sage 200 platform. In this first phase, the connection is read-only, so nothing is written back to Sage until the detection logic has proven itself in daily use.

Every night, the system imports and syncs customer records from Sage into the CRM automatically, so duplicate checks are always working from current data rather than a stale snapshot. Each potential match is then scored using a weighted algorithm that checks five separate signals:

• Phone Number
• Postcode Paired with Surname
• Address
• Company Name
• Email Domain

Weighing several signals together, rather than relying on a single field, is what keeps the detection accurate across such a varied set of records.

Only the clearest, safest matches are merged automatically. Anything short of that certainty is routed to a member of the Collins Nets team for a quick yes or no decision, presented side by side in a review panel and colour-coded by confidence so staff can triage at a glance. Nothing is ever merged blind.

Automation with Guardrails, Not A Black Box

The auto-merge threshold was deliberately set on the conservative side. Nothing merges automatically unless multiple independent signals agree, and an exact phone number match is a hard requirement in every case. It's a system built to earn trust gradually, catching the obvious duplicates without ever taking a risk on the ambiguous ones.

Once Collins Nets started using the system day to day, a few edge cases came to light that only show up when real customer data meets real business practice. Rather than treating these as problems, b4b treated them as the next round of refinement.

Customers who legitimately hold both a business and a personal account, often sharing the same phone number or address, are now protected from being wrongly merged into one. Records that share a matching phone number but list a different billing address are automatically held back for human review instead of being merged outright. A new "before merging" panel also surfaces contact details that Sage's own native merge tool would otherwise silently discard, so nothing gets lost in the process.

This is what a genuinely collaborative build looks like. Collins Nets used the system, flagged what didn't quite fit their business, and b4b closed those gaps. The result is a tool shaped by the way the company actually operates, not just how the data looked on paper.

What's Next: Phase 2

With the detection logic proven, the next phase moves the system from read-only to read and write. Duplicate records will be deactivated in Sage automatically; review decisions will be actioned directly via API and contact details will be copied across before a merge without any manual steps. An undo function is also being built in, so any merge can be reversed if something doesn't go to plan.

This next stage is being developed and tested in a safe environment first, with production rollout only happening once Collins Nets has formally signed it off. It's a deliberately cautious, phased approach, one that puts the safety of the client's data ahead of speed.

b4b works with businesses across Dorset and beyond to build the kind of systems that solve real operational problems, not just add another dashboard to log into. If duplicate data, manual processes, or disconnected systems are holding your business back, call our team on 01202 684400 or complete our contact form to get in touch today.