How much does PLC programming cost? Real prices 2026

If you are collecting quotes to automate a machine or refurbish a line, the first question is always the same: how much does PLC programming cost? Here are real market figures from Spain, what that price includes (or should include) and which factors push it up or down.

How much does it cost to program a PLC?

Programming a PLC costs between €3,000 and over €25,000 depending on project size, with engineering rates of €55–85 per hour in Spain. A small project (simple machine, a few dozen I/O) runs around €3,000–8,000; a mid-size one (line or process with communications and HMI), €8,000–25,000; and a complex one with SCADA, functional safety and several stations exceeds €25,000.

These ranges are orientative and come from our experience as system integrators: every plant, every process and every starting point is different. But they serve the important purpose: spotting both the inflated offer and the suspiciously cheap one. This table sums up the three scenarios:

1 What PLC programming (really) includes

"Programming a PLC" is not sitting down to write code on day one. In a professional project, code is just one of five phases — and not the longest one:

As a rule of thumb, pure coding rarely exceeds 40% of the project hours; analysis, testing and documentation take the rest. That is why a very cheap offer almost always cuts corners there: in what you don't see on day one but pay for over the whole life of the machine.

2 The factors that move the price

Two machines with the same PLC can cost twice as much one as the other. These are the factors that really move the budget:

Number of I/O and process complexity

Inputs/outputs are the quickest thermometer of project size: every signal must be defined, wired into the program, tested and documented. But careful: 50 I/O of a process with recipes, dosing and traceability take more work than 150 I/O of on/off conveyors. The complexity of the logic weighs more than the raw count.

Functional safety (ISO 13849-1)

If the machine poses risks to people —and almost all do—, the safety circuit must be designed and validated according to ISO 13849-1: required performance level (PL), emergency stop functions, door interlocks, safety PLCs or relays. It adds engineering hours and specific hardware, but it is not optional: it is CE marking.

Communications and integration

An isolated PLC is increasingly rare: it must be integrated with drives over Profinet, with scales or analysers over Modbus, with the SCADA over OPC UA, sometimes with the ERP. Every gateway and every protocol adds configuration and testing hours. If you are unsure about the control and supervision layers, our comparison SCADA vs PLC makes it clear.

Retrofit vs new machine

Programming a new machine means starting from a blank page. A retrofit —replacing an obsolete PLC while keeping the machine— requires reverse-engineering an old program, often undocumented, and living with inherited wiring. That is why a retrofit can cost as much or more in engineering than a new project, even though it saves a lot on mechanics. If your project is a full line, see our guide on how much it costs to automate a production line.

Deadlines and site conditions

One factor everyone forgets until the end: the calendar. Commissioning during a two-day plant shutdown, working nights so production does not stop, or travelling to a remote site all add hours and surcharges that a comfortable schedule avoids. If your window is a summer or Christmas shutdown, close the offer months earlier: booking automation engineers at the last minute is as expensive as booking flights that way.

3 Siemens or Allen-Bradley? What changes in the price

It is the star question, and the honest answer is: in engineering hours, almost nothing. A good programmer takes about the same time to solve the same process in TIA Portal (Siemens) as in Studio 5000 (Allen-Bradley/Rockwell). What does change is the environment:

Our advice is neutral: if your group already has a corporate standard, stick to it — the maintenance savings outweigh any licence difference. If you are starting from scratch in Spain, the Siemens ecosystem usually works out cheaper thanks to the availability of spares and programmers.

4 Why documented code is worth more (and cheap turns out expensive)

Two programs can run the same machine and be worth a fraction of each other… five years later. A structured, commented program lets any technician diagnose a fault at 3 a.m. without calling the author; a "spaghetti" one turns every stoppage into a forensic investigation.

Documented code costs more hours today, but it is the difference between a 20-minute stop and a 4-hour one for the entire life of the machine. When comparing offers, always ask: is the code delivered commented and with a backup? Is there an alarm manual? Does the naming follow a standard? If the answer is vague, you will pay the initial saving back with every breakdown. It is the same logic we apply in our industrial process automation projects: the program is a plant asset, not a supplier's black box.

5 Warning signs of a poor quote

Before signing, run the offer through this list. Every failed point is a disguised extra cost:

• No functional analysis up front: if nobody writes down how the machine must work, you will pay for the commissioning "surprises" as extras.
• The scope fits in one line: "PLC and HMI programming" without an I/O list, operating modes or test protocols is not a scope — it is a blank cheque.
• No mention of safety: if the offer says nothing about ISO 13849-1 or safety validation, either the machine doesn't need it (rare) or someone is ignoring it.
• Documentation is "optional": uncommented code with no manual means lifelong dependency on the supplier.
• No defined warranty or support: who responds, within what time and at what rate when something fails after three months?
• The price is too good: below market rate nobody gives hours away; they cut them from testing and documentation — exactly what protects you.

Frequently asked questions