Migrating an Access database to a web app cost in London (2026)

The verdict in three sentences

An Access or Excel file shared by more than 5 users almost always ends up corrupted, losing its history or blocking remote work, and when it breaks, invoicing and customer credit control stop with it. Migrating to a web app costs GBP 15,000 to 60,000 with a London agency as a 2026 estimate, or roughly EUR 3,810 to 10,670 for simple to mid-size apps on Kolonell's nearshore grid, plus data migration. For an SME whose turnover runs through that file, the investment often pays back within 18 to 30 months through fewer credit and stock errors alone.

The real risks of a shared Access file

The typical case: a food wholesaler in East London, 12 users (sales reps, warehouse staff, bookkeeper, managing director), a 1.2 GB Access file on a desktop acting as a server, and Excel extracts emailed to reps on the road in Essex and Kent.

Microsoft ended support for Office 2016 and 2019 in October 2025, so many legacy Access front ends now run on unpatched software. Under UK GDPR, a customer database on an unsupported desktop without backups is hard to defend if the ICO comes asking after a breach.

What the migration costs: the 2026 grid

The wholesaler fits the mid-size profile: sales, stock across two warehouses, customer credit with limits and reminders, and a dashboard for the director. Data migration is the item not to underestimate: a years-old Access file contains duplicate customers, inconsistent balances and repurposed fields.

The method that avoids business disruption

A successful migration is not a weekend job. It follows four steps: an audit of the existing file (tables, queries, macros, printed reports) over 1 to 2 weeks; modular development over 6 to 10 weeks; a parallel run of 2 to 4 weeks comparing customer balances and stock between old and new systems; then cut-over, with the old file frozen read-only. Printed documents the team knows (delivery notes, customer statements) should be reproduced faithfully to ease adoption, and an Xero or Sage export usually closes the loop with accounting.

Mini case study

Tom, managing director of the wholesaler, estimates current losses: 2 % of customer credit written off for lack of follow-up on an average GBP 400,000 ledger, or GBP 8,000 a year, plus 1.5 % stock discrepancies on GBP 1.4 M of goods sold, or GBP 21,000. Add 10 hours a week of re-keying at GBP 20 an hour, about GBP 10,400 a year. Total: GBP 39,400 a year. With a mid-size London build at GBP 42,000, GBP 4,000 of data migration and GBP 6,000 yearly maintenance, and assuming a 70 % reduction in those losses, net yearly gain reaches about GBP 21,600. Payback comes around month 26; on a nearshore budget the same scope pays back in well under a year.

FAQ

How much does it cost to migrate an Access database to a web app in London?

As a 2026 estimate, expect GBP 15,000 to 30,000 for a simple app and GBP 30,000 to 60,000 for a mid-size app with a London agency. Nearshore teams such as Kolonell price the same scopes at EUR 3,810 to 10,670.

Can we keep our historical data?

Yes, migration includes sales history, customers and balances after cleansing. Plan 1 to 2 weeks of balance checks before cut-over.

Is Access still supported by Microsoft?

Access in Microsoft 365 is still supported, but Office 2016 and 2019 lost support in October 2025. Multi-user Access files also remain fragile beyond 5 to 10 concurrent users.

How long does the project take?

Count 10 to 16 weeks overall, including a 2 to 4 week parallel run. Operations never stop during the migration.

What does the app cost after delivery?

Kolonell maintenance runs 35,000 to 120,000 FCFA a month depending on level, 75,000 FCFA (EUR 110) for Standard. Hosting adds roughly GBP 30 to 150 a month.

Let's scope your project. Send us your Access or Excel structure and user count: we will price the scope, indicative budget and migration timeline. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.