The verdict in three sentences
Migrating data to a new application costs between EUR 5,000 and EUR 25,000 excl. VAT in 2026, with price driven by volume, number of sources and the quality of the source data. The most underestimated item isn't the transfer but the cleaning: dirty data migrated stays dirty and pollutes the new tool from day one. Strategy (big-bang or progressive) and rollback capability determine the risk level far more than the budget itself.
What makes up the budget
Migrating isn't copying: it's auditing, cleaning, transforming, loading, then proving nothing was lost. Reconciliation (comparing source and target) is what separates a serious migration from a risky copy-paste.
| Item | Low volume | Medium volume | High volume |
|---|---|---|---|
| Audit & mapping survey | EUR 1,000 | EUR 2,500 | EUR 4,500 |
| Cleaning & deduplication | EUR 1,200 | EUR 3,500 | EUR 6,500 |
| Mapping & ETL scripts | EUR 1,500 | EUR 4,000 | EUR 7,000 |
| Reconciliation tests | EUR 800 | EUR 2,500 | EUR 4,000 |
| Cutover & post-migration support | EUR 500 | EUR 1,500 | EUR 3,000 |
| Total excl. VAT (2026) | EUR 5,000 | EUR 14,000 | EUR 25,000 |
High volume typically means more than 500,000 records spread across several heterogeneous sources (Excel, legacy software, SQL database).
Big-bang vs progressive migration
Strategy choice changes the risk and rollback cost. Big-bang switches everything over in one night; progressive migration keeps old and new systems side by side for a period.
| Criterion | Big-bang | Progressive |
|---|---|---|
| Cutover duration | 1 weekend | 4-12 weeks |
| Risk | High (all or nothing) | Moderate |
| Rollback cost | EUR 2,000-6,000 | Low (partial return) |
| Temporary sync cost | EUR 0 | EUR 2,000-5,000 |
| Business impact | Heavy on D-day | Smoothed |
| Suited to | Small volumes | Critical volumes |
For an SME that can't stop operating, progressive migration costs more but avoids the catastrophe scenario of a rollback in the middle of business hours.
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Mini case study
An accounting firm in Toronto changes its practice software and must migrate 12 years of data: 8,000 clients, 240,000 invoices, split between the legacy software and 30 Excel files. The quote comes to EUR 16,500 excl. VAT for a progressive strategy, including EUR 4,800 of cleaning (11% duplicates detected). Without cleaning, the firm would have imported 26,400 duplicate records, generating billing errors estimated at 15-20 hours/month of manual correction, about EUR 8,400/year. Cleaning therefore pays back in under 8 months, excluding reliability gains.
FAQ
Why does cleaning cost so much? Because you must detect duplicates, harmonize formats (dates, phones, addresses) and resolve conflicts. It's 20-30% of budget but it's what guarantees a clean new system.
Can I migrate myself with an export/import? For a few hundred clean records, yes. Beyond that, the lack of reconciliation means you don't know what was lost: it's the top failure factor.
How long should I keep the old system? Plan 3 to 6 months of read access after cutover, to verify and reassure teams. It's cheap and prevents a lot of panic.
What is a reconciliation test? It's the quantified comparison between source and target (record counts, sum of amounts). Expect EUR 800 to 4,000: it's your proof nothing was lost.
What budget for a rollback? For big-bang, plan EUR 2,000 to 6,000 for the ability to revert. For progressive, rollback is partial and far cheaper.
Let's scope your project. Tell us the record volume, number of sources and target software: we'll assess data quality and recommend big-bang or progressive. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
