What does it cost to keep running once it is built?

A client said to me, about a previous supplier: I didn't have that sort of clear conversation with him, saying how much is this going to cost to maintain.

He found out later. Do not be him. Here is what actually makes up the ongoing cost.

The three separate things people merge into one

1. Running costs. Hosting, database, AI usage. These are third-party bills and they should be in your name, at cost, with no margin. Typically modest — tens of pounds a month for most small systems, more if AI usage is heavy. Anyone marking these up should explain why.

2. Support. Someone answers when it breaks. This is a real service with a real cost and it should have a defined response time. If it does not have a response time, it is not support, it is goodwill.

3. Change. Your business changes, so the software has to. This is not a fault, it is the point. Budget for it as a small ongoing allowance or as occasional paid work, but budget for it either way.

What to insist on

• The running costs itemised and billed at cost, with the receipts.
• A monthly support figure with what it covers and a response time in writing.
• No lock-in. One client told me plainly he was fine with the monthly figure as long as he was not tied into anything. He was right, and I agreed on the spot.

The number to hold in your head

As a rough planning figure, expect ongoing costs somewhere around 15 to 20 per cent of the build value annually, covering all three. If a supplier quotes a build with no ongoing conversation at all, they have either forgotten or they are hoping you will.