We run a copywriting agency. So we're biased. But the honest answer is: it depends — and the variables are simpler than people pretend.
I run a copywriting agency, so I should tell you to hire an agency. I won't. The right answer depends on three things, and most companies pick wrong because they don't ask them in this order.
Question 1: How much copy do you need per month?
Under 8,000 words a month: hire an agency or a freelancer. The cost of recruitment, payroll, and management for an in-house hire isn't justified.
Over 30,000 words a month and the work is recurring (blog, social, product, email): hire in-house. You'll pay less per word and have someone who knows the business deeply.
Between 8,000 and 30,000: this is where it gets interesting. Often the answer is a smaller in-house writer + an agency for big-bet pages (homepage rewrites, launches, About).
Question 2: Does the work need deep product knowledge?
Technical SaaS, regulated industries, complex services — these benefit from someone who lives the business. An in-house writer learns the product in months; an agency learns it in days, and never as deeply. If the writing requires nuance only insiders catch, hire in-house.
If the writing is more about craft than knowledge (landing pages, brand voice, About, ad copy), an agency wins. We see ten times more of those pages than any in-house writer ever will, and pattern recognition matters.
Question 3: How important is brand voice consistency?
An in-house writer naturally develops voice consistency over time. An agency has to be told. And: a single in-house writer becomes a single point of failure when they leave (and they will, eventually).
The hidden cost of in-house: when your writer leaves, voice continuity often dies with them. Agencies are more replaceable, which is both a downside (less depth) and an upside (less risk).
The pricing truth
Mid-level copywriter in the UK: ~£55-75k all-in. That's £4,500-6,200/month. A retainer agency at the same level: ~£3,000-5,000/month. The in-house hire is more expensive per month and writes more per month. So per-word, in-house is cheaper — once the volume is there.
Below the volume break-even point, the agency is dramatically cheaper. Above it, the in-house hire is. Most companies overestimate their volume needs (and underuse the in-house hire) for the first year.
The honest verdict
Start with an agency. Watch your real monthly word-count for six months. If it stabilises above 25,000 a month, hire in-house. If it doesn't, stay with the agency. Most companies that try to do this in reverse end up with an under-utilised in-house writer they're afraid to let go.
