Notes · 5 November 2026
The £4,500 mistake.
Offices worry about how long a quote takes. The number that really hurts is how far off it is. Three per cent on an ordinary tender is £4,500 gone.

Most offices worry about how long a quote takes. Speed matters. But the number that really hurts is how far off the quote is.
Take an ordinary tender, say £150,000. Be 3% under, and £4,500 has gone before a single drawing is issued. Nobody notices on the day. It shows up months later as a job that "never quite washed its face".
Where 3% hides
It's rarely one big mistake. It's usually a few small ones:
- Old rates. The rate sheet was last updated before the price of everything went up.
- A scope line nobody wrote down. The client assumed the connection design was included. The quote didn't say either way.
- Missing exclusions. Galvanising, site measures, a second round of comments.
- The job that looked like the last one. Similar isn't the same, and the difference is in the connections.
- Friday afternoon. Enough said.
Catching it before it goes out
Redpen drafts each quote from your current rate book, so today's rates are the starting point, not last year's. The scope is written out line by line, with the exclusions, so the client sees what's in and what isn't. And if the price falls below the margin you've set, it's flagged before it's sent.
A person still reviews every quote. Redpen just makes the 3% easier to see.
What did yours teach you?
Every estimator has one job they still think about. What did your worst estimate teach you? The best answers might end up in a future post, anonymously of course.
Redpen is in early access with a small number of firms.
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