Interactive demo

Clean up a customer file before analysing it

A typical CRM export. Drag the slider to compare the raw file with the cleaned one.

customers_export.xlsx · sample
Before
#CustomerEmailPhoneDateCityAmount
1SMITH johnj.smith@gmail07700 90012303/02/2024london1,250.00 EUR
2Smith Johnj.smith@gmail.com+4477009001232024-02-03London 1250
3jones emmaEMMA.JONES@OUTLOOK.COM0770090045615 March 2024LEEDSempty
4Brown Olivero.brown@yahoo.co.uk7700 900 7892024/04/22Bristol890 €
5Taylor, Gracegrace.taylor@bt.com07700.900.32101-05-2024Manchester2 100
6BROWN olivero.brown@yahoo.co.uk 07700 900 78922/04/2024bristol890
After
#CustomerEmailPhoneDateCityAmount
1John Smithj.smith@gmail.com+44 7700 90012303/02/2024London€1,250
2— merged into row 1
3Emma Jonesemma.jones@outlook.com+44 7700 90045615/03/2024Leedsmissing
4Oliver Browno.brown@yahoo.co.uk+44 7700 90078922/04/2024Bristol€890
5Grace Taylorgrace.taylor@bt.com+44 7700 90032101/05/2024Manchester€2,100
6— merged into row 4
  • 2 duplicates merged
  • 1 invalid email fixed
  • 6 phone numbers in international format
  • 4 dates standardised
  • 6 names, cities and amounts standardised
  • 1 missing value flagged

The cleaning is written once (Power Query, SQL or Python), then re-run automatically on every new export.

Demo on sample data. The data is made up; the approach is the one I use on real projects: the same KPIs, the same consistency checks. Typical engagement: CRM cleanup and sales pipeline tracking.

The same cleanup on your files? Write to me

The context

Duplicates, mixed date formats, names spelled three different ways, empty cells: with dirty data, every analysis is wrong before it even starts. In this example, leads also slip through because follow-ups aren’t tracked.

How I built it

  1. Assessment

    I measure data quality: duplicates, gaps, inconsistencies.

  2. Cleaning

    A repeatable pipeline, re-run on every import, not a one-off manual clean.

  3. Standardisation

    Fields and pipeline stages defined once and for all, with data-entry rules so the problem doesn’t come back.

  4. Tracking

    A pipeline tracker with automatic follow-up reminders.

Before and after

Before

  • Duplicates and inconsistent fields
  • Poorly defined pipeline stages
  • Forgotten leads, irregular follow-ups

After

  • Deduplicated, standardised database
  • A readable pipeline, stage by stage
  • Automatic follow-up reminders

What it changes

Reliable numbers for every analysis that follows. Cleaning you can re-run in one click. Fewer forgotten leads.

What about your business?

No need to start from scratch: the cleaning runs on your existing files, from a few hundred rows to several million, using SQL or Python when Excel is no longer enough.

Need something similar? Write to me.

Tell me about your project