Small companies collect contacts for years: customer lists exported from a shop, a spreadsheet a colleague started, a CRM that three different people have filled in. The result is predictable. The same person appears twice, a phone number is written four different ways, and half the records have no company name.
Cleaning that data is a service people pay for, and the entry cost is low.
What the work involves
There are three parts. Deduplication finds repeated contacts and merges them. Normalization puts every field into one format, so names, phone numbers and addresses sort and import without errors. Enrichment fills the gaps, such as a missing company name or website, so the list is ready for the next campaign.
Most of it can be scripted. Roughly 60% of the process can run automatically with a short Python script and an AI assistant to suggest fixes, while a person checks the edge cases before the file goes back to the client.
What you need to start
Advanced spreadsheet skills and an eye for detail matter most. Python and SQL help, but they are optional. The tools can all be free: Google Sheets, OpenRefine, and Python with pandas. Plan for about 5 hours a week, a starting budget between $0 and $100, and roughly €15 a month in running costs.
Finding clients
The channels that fit this service are freelance marketplaces such as Guru and Upwork, and direct outreach to small businesses that clearly keep their contacts in spreadsheets. A first client typically takes around three weeks to land.
Things to settle early
Agree with the client what a clean file looks like before you start, so both sides measure the result the same way. And because contact lists contain personal data about other people, treat GDPR seriously: work only on data the client is entitled to share, and keep the files secure.
Growing it
A one-off cleanup can turn into a monthly data maintenance package, which gives you recurring income with the same clients.
If you want to see how this service compares with other AI-assisted ways to earn from your own skills, time and budget, you can check your profile on Kairo: https://ai-income-matcher.kairo-app.workers.dev
