The verdict in three sentences
For a firm with 900 client files, a custom document upload portal costs 18,000 to 40,000 EUR excl. VAT (about 15,500 to 34,500 GBP), delivered in 10 to 14 weeks, with automatic reminders and invoice OCR. Off-the-shelf tools billed at 3 to 9 EUR per client per month come to 32,000 to 97,000 EUR a year at this volume. Above roughly 400 clients, custom becomes cheaper over 5 years, provided the scope is tightly controlled.
What a document upload portal must do in 2026
The real need is simple: get the right document, from the right client, before the deadline, without staff spending their days writing "could you send us your March statements?". The table below lists useful features and their indicative development cost.
| Feature | Concrete use | Indicative 2026 cost (EUR excl. VAT) | Priority |
|---|---|---|---|
| Secure client area | Magic link login or two-factor authentication | 3,500 | Essential |
| Mobile upload | Photo of a receipt from a smartphone, automatic compression | 3,000 | Essential |
| Checklist per client | Expected documents per month, received or missing | 4,500 | Essential |
| Automatic reminders | Email then SMS at D-10, D-5 and D+2 of the deadline | 2,500 | Essential |
| Invoice OCR | Reads supplier, date, net amount and VAT | 6,000 | High |
| Export to production software | File or API to Xero, Sage, IRIS or CCH | 5,000 to 9,000 | High |
| Firm dashboard | Completion rate per staff member and client | 3,500 | Useful |
| Per-document messaging | Staff question attached to the document | 2,500 | Useful |
An MVP limited to the four essential features comes to around 18,000 EUR excl. VAT. The full version with OCR, export and dashboard reaches 35,000 to 40,000 EUR excl. VAT.
5-year cost: off-the-shelf vs custom
Calculation for 900 active clients. The custom option includes 30,000 EUR excl. VAT of development, European hosting, corrective and evolutive maintenance (about 6,000 EUR a year) and OCR at about 0.01 EUR per page for 36,000 documents a month.
| Year | Off-the-shelf at 3 EUR/client/month | Off-the-shelf at 6 EUR/client/month | Custom portal |
|---|---|---|---|
| Year 1 | 32,400 EUR | 64,800 EUR | 40,300 EUR |
| Year 2 | 32,400 EUR | 64,800 EUR | 10,300 EUR |
| Year 3 | 32,400 EUR | 64,800 EUR | 10,300 EUR |
| Year 4 | 32,400 EUR | 64,800 EUR | 10,300 EUR |
| Year 5 | 32,400 EUR | 64,800 EUR | 10,300 EUR |
| 5-year total | 162,000 EUR | 324,000 EUR | 81,500 EUR |
These are 2026 orders of magnitude. Vendors often grant volume discounts above 500 clients, which can bring the price down to 2 to 3 EUR. Custom then remains competitive from year three, and the firm owns the code and the data.
10 to 14-week schedule
Weeks 1 and 2: workshops with 2 or 3 staff members, mapping documents by engagement type (sole traders, companies, property, payroll). Weeks 3 and 4: mock-ups tested by 5 pilot clients. Weeks 5 to 10: development in 2-week iterations. Weeks 11 and 12: connector to the production software and OCR testing on 500 real invoices. Weeks 13 and 14: gradual rollout by staff portfolio. Security follows professional body guidance: European or UK hosting, encryption, access logging, GDPR-compliant retention.
Mini case study
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Isabelle Roux, partner at a 900-client accounting firm in Nantes (the same maths applies to a London practice), measured 6 hours of chasing per week across her team, 276 hours a year over 46 weeks. At an internal cost of 75 EUR an hour, that is 20,700 EUR a year, not counting late VAT returns. She launched a 30,000 EUR excl. VAT portal with OCR and reminders. After 6 months, manual chasing fell to 1.5 hours a week and invoice entry dropped by 35 %. The annual gain on chasing alone reaches 15,500 EUR, plus about 12,000 EUR of data entry time saved: the portal pays for itself in 13 months.
FAQ
Is a custom portal more secure than an off-the-shelf tool?
Not automatically. Security depends on encryption, two-factor authentication and penetration testing, which cost about 3,000 to 5,000 EUR a year. We include them in the maintenance budget.
What OCR accuracy should we expect?
On standard supplier invoices, 90 to 95 % of key fields are read correctly. Crumpled till receipts drop to around 70 %, hence a validation step by staff.
Will clients actually use it?
With smartphone photo upload and SMS reminders, firms see 60 to 80 % adoption within 3 months. Remaining clients email an address that feeds the portal.
Can we start small?
Yes, an 18,000 EUR excl. VAT MVP with client area, mobile upload, checklist and reminders is delivered in 10 weeks. OCR and export come in phase 2.
Who hosts the data?
A certified host in Europe or the UK, for 150 to 300 EUR a month depending on volume, with daily backups kept for 30 days.
Let's scope your project. Share your number of clients, your production software and the time lost chasing documents: we will price a portal between 18,000 and 40,000 EUR excl. VAT, delivered in 10 to 14 weeks. 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.
