The verdict in three sentences
An API integration between your website, your CRM (HubSpot, Salesforce) and your ERP removes double data entry and pushes data accuracy above 98%. In 2026 in London, budget 8,000 to 30,000 EUR depending on the number of flows and mapping complexity, delivered in 4 to 10 weeks. A middleware iPaaS speeds the project up but creates a monthly dependency you must budget over three years.
What an API integration costs in 2026
Price depends mostly on the number of flows (a flow = one direction for one data type, e.g. "new CRM customer to ERP") and the richness of field mappings. Here are 2026 orders of magnitude for the London market.
| Scope | Synced flows | Timeline | Cost 2026 (EUR) |
|---|---|---|---|
| Single simple flow | 1 (site leads to CRM) | 1-2 wks | 8,000 - 12,000 |
| SME standard | 3-4 (customers, quotes, invoices) | 4-6 wks | 12,000 - 20,000 |
| Full bidirectional | 5-7 with replays | 6-8 wks | 20,000 - 28,000 |
| Multi-system | 8+ with middleware | 8-10 wks | 25,000 - 30,000+ |
| Annual maintenance | monitoring + changes | ongoing | 15-20% of build/yr |
Managed iPaaS or custom development
An iPaaS (Make, Zapier, n8n, Workato) wires ready-made connectors; custom builds code direct API calls and fine-grained business logic. The right choice depends on how stable your processes are.
| Criterion | Managed iPaaS | Custom API |
|---|---|---|
| Upfront cost | 3,000 - 8,000 EUR | 12,000 - 28,000 EUR |
| Recurring cost | 500 - 2,000 EUR/mo | hosting < 100 EUR/mo |
| Setup time | 2-4 weeks | 4-10 weeks |
| Specific business cases | limited | unlimited |
| Vendor lock-in | high | low |
| High volume (>50k calls/mo) | expensive | economical |
Simple rule: under 10,000 operations/month with standard fields, iPaaS wins. Beyond that, or with proprietary business rules, custom pays back within 18-24 months.
Mini case study
Claire, CFO of a 45-person industrial SME in London, re-keys every Salesforce quote into her Sage ERP: about 12 hours/week across two assistants, with a 4% entry error rate. A bidirectional connector at 18,000 EUR (delivered in 6 weeks) automates quotes, customers and invoices. Result: 0.3 FTE freed, roughly 13,000 EUR/year, plus the end of error-driven credit notes (estimated at 6,000 EUR/year). Payback in ~11 months, before counting the gain in commercial data reliability.
FAQ
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Do we need to rebuild the site to integrate it with the CRM/ERP?
Not in most cases: if the site exposes an API or a modern CMS, flows plug in without a rebuild. A rebuild is only justified when the tech base is obsolete (fewer than 15% of projects).
How soon do we see benefits?
The first flow (often leads to CRM) ships in 1 to 2 weeks. Productivity gains become measurable within the first month of stable use.
What happens if an API goes down or returns an error?
A serious project includes a queue, automatic replays and alerts. No quote or invoice should ever be lost: it is a non-negotiable requirement of the spec.
Does HubSpot vs Salesforce change the price?
Marginally. Salesforce offers a richer but more verbose API; HubSpot is faster to wire. The cost gap stays under 15% on a standard project.
Can we start small then extend?
Yes, and it is recommended: we ship 1-2 priority flows, measure, then add the rest in batches. This smooths the budget and reduces risk.
Let's scope your project. Tell us your tools (CRM, ERP, billing), the number of target flows and your indicative budget, and we will frame the architecture and sequencing. 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.
