The verdict in three sentences
A custom client portal for an accounting firm costs between 30 000 and 80 000 GBP in 2026, depending on the number of modules (document management, e-signature, case tracking, invoicing) and the depth of integration with the production software. The realistic timeline is 3 to 5 months, with maintenance of 600 to 1 500 GBP/month. The payback comes from the 5 to 8 hours saved per week per staff member on document collection and follow-ups.
What the budget of an accounting portal covers
The price mainly depends on functional depth and the connection to the production software (Xero, Sage, IRIS, QuickBooks).
| Module | Scope | Indicative 2026 cost (GBP) |
|---|---|---|
| Portal core + authentication | SSO, client accounts, roles | 9 000 - 16 000 |
| Document management & exchange | Secure upload, auto filing | 7 000 - 14 000 |
| E-signature | eIDAS/QES, signing journey | 5 000 - 10 000 |
| Case & task tracking | Statuses, notifications, reminders | 6 000 - 13 000 |
| Production tool integration | API/connector, sync | 7 000 - 18 000 |
| Testing, training, go-live | QA, GDPR, documentation | 5 000 - 9 000 |
Custom build or off-the-shelf SaaS?
SaaS portals are fast but constrain the client journey and your brand. A custom build costs more upfront but pays off over time.
| Criterion | SaaS subscription | Custom portal |
|---|---|---|
| Year 1 cost | 4 000 - 15 000 GBP/yr | 30 000 - 80 000 GBP |
| Year 3 cost (cumulative) | 12 000 - 45 000 GBP | 42 000 - 104 000 GBP |
| Brand customisation | Limited | Full |
| Production integration | Standardised | Bespoke |
| Code ownership | No | Yes |
| Time to deploy | 2 - 6 weeks | 3 - 5 months |
Mini case study
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Claire, a partner at an 18-strong firm in London, deploys a portal at 56 000 GBP with document management, e-signature and Xero sync. Each staff member saves 6 hours/week on document collection, roughly 250 hours/year per person. Across 18 people at a loaded cost of 40 GBP/hour, the theoretical annual saving exceeds 180 000 GBP in productive capacity; the investment plus maintenance (13 200 GBP/year) is absorbed within the first months of the first filing season.
FAQ
How much is annual maintenance? Expect 600 to 1 500 GBP/month, i.e. 7 200 to 18 000 GBP/year, covering secure hosting, updates, minor enhancements and support.
Can the portal connect to our production software? Yes, via API or a dedicated connector. Integration is 7 000 to 18 000 GBP depending on whether the vendor exposes a documented API.
Is the e-signature compliant? Yes, using an eIDAS/QES provider (simple or advanced level). The integrated signing module costs 5 000 to 10 000 GBP.
How soon before a usable first version? A pilot on one module (document management + client accounts) ships in 6 to 8 weeks; the full portal in 3 to 5 months.
Is the data GDPR compliant? Yes: UK/EU hosting, access logging, encryption and a records-of-processing register are included in the QA phase.
Let's scope your project. Tell us your priority modules (document management, e-signature, tracking), your production tool and headcount for a precise quote, indicative budget 30 000-80 000 GBP. 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.
