

One website on a flat monthly retainer is a reasonable decision. Ten websites on the same flat retainer is somebody else’s business model, and you are funding it.
A client we now work with used to pay three hundred pounds a month, per website, to the agency that built them. Plus hosting. The build itself had been quoted at a normal rate, which was fair enough.
On one site that is an easy thing to sign. It sounds like sensible housekeeping. The problem only appears when you have ten.
Three hundred a month, ten times over, is thirty six thousand pounds a year before anybody has done a single piece of work. That is the standing charge for the estate existing.
And it was flat. A quiet month cost the same as a busy one. A site that needed nothing for a quarter cost the same as the one being rebuilt.
One site at that price is a decision. Ten is a business model.
We charge one retainer for the whole estate rather than a fee per site. Just under fifteen sites at the moment, for a thousand a month. That is not a discount, it is a different unit. You are paying for access to us, not for the privilege of each website continuing to exist.
It goes up with inflation, and if the estate grows by a couple of sites it might go up by a hundred or two. It does not go up by three hundred every time something new launches, because that would be taking the mickey and everybody involved would know it.
Every one of those sites was built on WordPress, which should mean you can move it anywhere. These could not be moved. Something in the setup tied them to that host, so you could not rehost them and you could not take a working copy away.
We have never encountered that anywhere else, before or since. We had to deal with it on every single site we took over. Whatever the intention behind it, the effect is that leaving costs you a rebuild, which means the retainer is not really a choice.
One site had to be rebuilt to get it out. We quoted a reduced rate and spread it across twelve months, so the first year cost more than doing nothing would have. From year two there was no three hundred a month, so it had paid for itself in a little over two years and kept paying after that.
That only works if you are willing to be worse off in the short term to be obviously better off later. Plenty of arrangements are built to make sure that trade is never available.
When the same client went through a brand refresh, they asked what it would cost to update the sites visually. Colours, some variations, applied across the estate. Nothing. It was covered.
We are paid twelve times a year. There are stretches, sometimes two or three months, where a client needs nothing at all beyond the hosting. Then there is a week where somebody asks for a set of changes and it takes a day. Invoicing for that day, on top of the retainer, is where a lot of these arrangements quietly go wrong. The retainer already covered the quiet months. That was the deal.
Some months you will not earn it. That is the arrangement working, not failing.
So when a client on a retainer asks what a change will cost, the answer is almost always nothing. I struggle to think of many occasions we have gone back with a number for tweaks and updates on a site we already look after.
Off a retainer it is simpler still. Small things we tend not to charge for at all. Anything bigger goes on at an hourly rate and lands on the next invoice, usually alongside the annual hosting, rather than arriving as a separate bill three days later.
The alternative is logging every fifteen minutes and charging for all of it. It is defensible, it is common, and in my experience it is roughly where a lot of clients quietly decide they do not much like their agency. Simple bits and pieces get itemised and marked up until asking for anything feels expensive.
Give and take works better in both directions. There are jobs where we have gone further than the scope because it was the right thing for the site. There are also months where we have been paid for very little. Over ten years those two things roughly cancel out, and what is left is a client who picks up the phone without bracing for a quote.
The version of this I would want repeated is short. They do not take the piss.
Add up every monthly fee across every site you own and look at the annual figure on its own. Then ask what it entitles you to, and whether you could move the sites tomorrow if you wanted. The second question matters more than the first.

The instinct when systems stop fitting is to replace all of it. That is usually the most expensive route available and the one most likely to fail halfway.
Travel is the clearest example, but the pattern holds in any sector: systems that used to take years to build are now a different size of problem entirely.
Your traffic can fall while your visibility rises. That sounds like agency nonsense until you look at where the answers are actually being read.