Almost every company that writes to us already has an ERP and a CRM, both working, both paid for, and one person whose job is moving information from one to the other. The conversation opens by asking for them “to talk to each other”, which sounds like a small problem and rarely is, though neither is it the monumental project some suppliers paint.
The first thing worth understanding is that integrating is not about connecting two programs. It is about deciding which of the two is in charge.
The decision to make before touching anything
A customer exists in the CRM and exists in the ERP. It has a name in each, sometimes a different one. It has a tax ID that carries hyphens in one and not the other. It might sit in the CRM as “López Industries Ltd” and in the ERP as “LOPEZ INDUSTRIES LIMITED”. Before moving a single record you have to decide which system is the truth for each field.
This decision is not technical and the supplier cannot make it. The usual split is that the CRM governs commercial data (contact, opportunity, deal stage) and the ERP governs fiscal and financial data (legal name, billing address, payment terms). Once that boundary is written down, the rest of the project becomes mechanical. When it is not written down, you end up with two systems overwriting each other and a team that no longer trusts either.
What actually needs integrating?
Very few people need everything synchronised with everything, though it is the first thing requested. The flows that genuinely return money are fairly narrow: a won opportunity in the CRM generating the order or invoice in the ERP without anyone retyping anything, the payment status from the ERP being visible in the CRM so sales does not call a defaulting customer as though nothing were wrong, and a customer record being created once, in one place.
Those three flows usually eliminate most of the manual work. The rest of the synchronisation requested in the first meeting, looked at calmly, turns out to be information somebody consults twice a month, which justifies neither the cost nor the risk of keeping it in sync.
What goes wrong in practice
Eighty per cent of the effort in an integration is not moving the data. It is deciding what to do when the data does not match.
The most common failure is not the connection dropping but the identifiers failing to match. If the CRM does not store the tax ID and the ERP does not store the email address, there is no reliable way to know that two records are the same customer, and the system quietly starts creating duplicates. That is why an honest integration spends its first weeks cleaning and unifying the customer master, work that is unglamorous and absolutely decisive.
Then there are runtime errors. A serious integration needs retries when the other system does not respond, a log of what happened, and above all an alert to a named person when something gets stuck. Without that, on the day it fails nobody will know until a customer complains. This point is what most distinguishes a professional integration from a bodge, and also what appears least often in cheap quotes.
What does it cost?
Connecting an ERP and a CRM that both have documented APIs, covering the flows above and with a customer master in reasonable shape, typically lands between €4,000 and €12,000, delivered within four to eight weeks.
That range escalates in two scenarios. First, when one of the systems has no API and data has to be extracted by indirect means, which also creates a fragile dependency that will break at the vendor's next update. Second, when the historical data is dirty and the project effectively becomes a clean-up job with an integration at the end. It is worth asking about this before signing, because it is usually what separates the initial quote from the final cost.
What to demand on delivery
- A document stating, field by field, which system governs what and in which direction each piece of data travels.
- Access to execution logs, so you can answer why one particular order never arrived.
- An automatic alert to a named person when something fails, not a dashboard nobody looks at.
- Credentials and code in the company's own accounts, not the supplier's. If the integration stops working the day you change consultant, it was never yours.
With those four deliverables, the integration outlives whoever built it, which is the only real proof the job was done properly.
The engagement is detailed in systems integration, and the full ranges on the pricing page.