Data Annotation · London
Data Annotation in London
Labelling data for London organisations training or evaluating machine learning models. Consistency matters more than volume here — annotators who disagree with each other teach a model to be uncertain in exactly the places where your business needed it to be decisive.
Why this comes up
The problem
A model needs training data and labelling has started without written guidelines. Different people are making different judgements on the same kind of example.
What you get
What we deliver
- Written guidelines covering the edge cases, since those cause the disagreement
- A pilot round measuring agreement between annotators before scaling up
- Labelling carried out against those guidelines, with questions fed back
- Inter-annotator agreement measured, so consistency is a number not a hope
- A held-out evaluation set labelled to a higher standard than training data
- A route to relabel as guidelines evolve, because they will
Want this scoped for your business in London?
Thirty minutes, no charge, no sales script. You leave with a written summary of what data annotation would actually involve — whether or not you use us.
Working in London
London
London clients usually come to us because they want senior people actually on their project rather than a large agency's B team, and because Midlands rates buy considerably more delivery per pound.
Clients here are usually replacing an agency, and want senior people on the work at rates that are not Central London rates.
Sectors we work with in London
- Financial Services
- Professional Services
- Technology
- Media
- Hospitality
- Retail
What we work with
Technologies and platforms
- Label Studio
- Python
- PostgreSQL
- AWS
- Prodigy
Who we work with
Industries we serve
- Healthcare
- Manufacturing
- Legal
- Retail
- Agriculture
Why us
Why London businesses choose Asionis
- Projects typically launched within 4–8 weeks
- No long-term contracts required
- All team members UK-based
- Dedicated account manager and development team
- Transparent reporting with monthly performance metrics
- Scalable from startup to enterprise
How we work
- Step 1
Free consultation
A 30-minute call to understand the problem. You keep the written summary either way.
- Step 2
Proposal
Scope, timeline and a fixed price, in writing, before anything starts.
- Step 3
Build
Short cycles with regular check-ins, so you see progress rather than hear about it.
- Step 4
Launch and support
We handle the go-live and stay available afterwards.
Other services in London
Looking for the full picture? See our Data Annotation services, everything we do in London or browse everything we do.
Data Annotation in London — common questions
- Why measure agreement between annotators?
- Because it caps how good the model can be. If two trained people disagree on a quarter of examples, the labels encode that inconsistency and the model learns it. Low agreement almost always means the guidelines are ambiguous rather than the annotators careless.
- How much labelled data do we need?
- Less than most expect if it is consistent — often hundreds to a few thousand examples for a focused task. A smaller, carefully labelled set reliably beats a larger inconsistent one, which is the opposite of how the question is usually framed.
- Can AI do the labelling?
- It can pre-label, with people reviewing and correcting, which speeds the work considerably. Fully automated labelling teaches your model to imitate another model's mistakes, so at minimum the evaluation set should be human-labelled.
- What about sensitive data?
- Annotation means people reading your data, so access controls, agreements and — where possible — anonymisation matter. For health or financial records this needs settling before any labelling begins, not as a later review.
- Do you work with businesses across Greater London?
- Yes. We are based in Leicester, United Kingdom and work with clients throughout London, including London and the surrounding Greater London area. Most collaboration happens remotely, and we travel for kick-offs and key milestones.
- What kind of London businesses do you usually work with?
- Clients here are usually replacing an agency, and want senior people on the work at rates that are not Central London rates. Beyond that we work across Financial Services, Professional Services, Technology, Media, Hospitality and Retail.
- Do you cover the areas around London?
- Yes — we work throughout London, including Reading, Milton Keynes, Cambridge, Brighton. London is an urban area of roughly 9,000,000+, and we take on work across the wider Greater London region rather than the city boundary alone.
Talk to us about Data Annotation in London
A 30-minute call with someone who would actually work on it. No sales script, no obligation.
- Projects typically launched within 4–8 weeks
- No long-term contracts required
- All team members UK-based
- Dedicated account manager and development team
- Transparent reporting with monthly performance metrics
- Scalable from startup to enterprise