The verdict in three sentences
For a Dublin accounting firm with 900 clients, a custom client portal for document upload and e-signature costs 30,000 to 60,000 EUR excluding VAT and takes 3 to 4 months to deliver. Against off-the-shelf SaaS licences billed at 8 to 15 EUR per client per month, custom pays back in 2 to 4 years, especially when the portal connects cleanly to your practice and accounting software (for example Xero, Sage or IRIS). The main gain is time: about 6 hours per staff member per month no longer lost chasing documents by email.
The real cost of email-based document exchange
In a 900-client firm, documents arrive by email, WhatsApp, USB stick or paper. Each staff member chases, renames, files and searches. Internal reviews often show that 10 to 15% of production time goes into these low-value tasks.
| Task | Average time per staff member per month | With a portal |
|---|---|---|
| Chasing missing documents | 2.5 h | 0.5 h (automatic reminders) |
| Filing and renaming | 2 h | 0.3 h (filed by client and period) |
| Searching for a document | 1.5 h | 0.2 h |
| Sending documents for signature | 1 h | 0.3 h (built-in e-signature) |
| "Did you receive it?" replies | 0.8 h | 0.1 h (status visible to client) |
| Total | 7.8 h | 1.4 h, about 6 h saved |
For a 15-person firm, that is roughly 90 hours per month, the equivalent of half a full-time role.
Off-the-shelf SaaS or custom portal: the numbers
Client portal SaaS for accounting firms is usually billed per active client. 2026 orders of magnitude:
| Criterion | Off-the-shelf SaaS | Custom portal |
|---|---|---|
| Upfront cost | 0 to 3,000 EUR (setup) | 30,000 to 60,000 EUR |
| Recurring cost for 900 clients | 7,200 to 13,500 EUR per month | 450 to 1,000 EUR per month (hosting, maintenance) |
| 3-year cost | 260,000 to 490,000 EUR | 46,000 to 96,000 EUR |
| Firm branding | Logo only | Full interface in your colours |
| Accounting software connector | Depends on vendor, sometimes missing | Built on your real workflows |
| Data hosting | Varies, sometimes outside the EU | EU (Ireland), GDPR-compliant |
| Roadmap | Vendor's priorities | Your priorities |
Note: many firms enable the SaaS for only part of their clients, which lowers the bill. At 300 active clients and 10 EUR per month, the annual cost falls to 36,000 EUR, and custom then pays back in about 2 years.
What a 30,000, 45,000 or 60,000 EUR portal includes
| Level | Features | Price | Timeline |
|---|---|---|---|
| Core | Document upload by period, status, automatic reminders | 30,000 EUR | 3 months |
| Standard | + e-signature, per-client messaging, mobile web app | 45,000 EUR | 3.5 months |
| Complete | + accounting connector, client dashboard, invoice OCR | 60,000 EUR | 4 months |
| Maintenance | EU hosting, backups, fixes | 450 to 1,000 EUR per month | Ongoing |
E-signature relies on a certified eIDAS provider (1 to 2 EUR per signature depending on volume). The accounting connector is the trickiest item: you must map journals, document categories and the period-matching rules.
Mini case study
Siobhan, partner at an accounting firm in Dublin (900 clients, 15 staff), compares a SaaS at 10 EUR per active client with a Standard custom portal.
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- Average loaded hourly cost of a staff member: 50 EUR.
- Time saved: 6 h x 15 staff x 50 EUR = 4,500 EUR per month, i.e. 54,000 EUR a year.
- Custom portal: 45,000 EUR + 700 EUR per month maintenance, i.e. 53,400 EUR in year one.
- SaaS for 600 active clients: 6,000 EUR per month, i.e. 72,000 EUR a year.
The custom portal pays for itself in under a year through time saved alone, and costs about 18,600 EUR less than the SaaS in year one, with the gap widening every following year.
FAQ
How much does a custom client portal cost for an accounting firm in Dublin?
Between 30,000 and 60,000 EUR depending on features, plus 450 to 1,000 EUR per month for maintenance and hosting. The mid-level option with e-signature sits around 45,000 EUR.
Can the portal connect to our accounting software?
Yes, through APIs or structured exports. The connector usually represents 7,000 to 14,000 EUR of the budget, depending on how many data flows must be synchronised.
Where are client documents hosted?
In the EU, with a certified host, file encryption and access logs. This is key to meeting GDPR and professional confidentiality obligations.
Will clients actually use the portal?
Adoption often exceeds 70% after 6 months if uploading from a smartphone takes under 30 seconds. Automatic reminders and gradually stopping email submissions do the rest.
How long before the portal goes live?
Plan 3 to 4 months, including 3 to 4 weeks of scoping with staff. A 1-month pilot on 50 clients lets you fix usability before full rollout.
Let's scope your project. Tell us your scope, current tools and timeline: we scope the project lot by lot and agree the schedule with you. 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.
