The quality of addresses in customer databases has deteriorated. This unsurprising finding comes from a regular study conducted by Deutsche Post subsidiary Post Direkt.
Study profile:
Initiator: Deutsche Post Direkt (subsidiary of Deutsche Post AG):
- Research period: 2024
- Basis: Analysis of 200 anonymized address cleansing projects, 20 from each industry.
Evaluation criteria:
- Addresses that cannot be delivered by mail
- Outdated addresses (person has moved/deceased)
- Buildings that cannot be delivered to
- Relocation information available
- Address corrections
- Duplicates
Focus industries: online retail, banking, insurance, tourism, consumer goods, public sector, among others
Management Summary: Condition has deteriorated!
The quality of addresses in German customer and prospect databases deteriorated slightly in 2025 for the first time in years. The proportion of undeliverable addresses rose from 12.6% in 2023 to 13.1%. The main reasons for this are relocations, deaths, spelling mistakes, and duplicates.
The best address data can be found
- in online retail (91.3% deliverable), followed by
- banks (90.4%) and
- insurance companies (89.0%).
- Bringing up the rear are the non-profit sector (16.5% undeliverable) and
- the public sector (18.2% undeliverable).
Key findings:
- One in eight addresses is incorrect.
- Duplicates, relocations, and typos remain the most common sources of error.
- Without correction, avoidable costs and CO₂ emissions are incurred.
My conclusion: You can do good things better and save a lot of money.
It’s not just undeliverable mail, but also spelling mistakes, old names due to marriage, or duplicates that annoy recipients. They ask themselves: What’s wrong with this company? Such silent annoyances ultimately lead to customers no longer placing orders or switching providers. Donation appeals end up in limbo and letters from public authorities arrive late. That’s not good.
Values of 91% or worse are really bad because they cost real money. Good values start at 95% or better.
Of course, those who do not send mail regularly (such as fundraisers or the public sector) do not have as many opportunities to check their own mailings. But the use of reference data and the various data pools available on the market (e.g., from e-commerce) can make a big difference.
Address quality in customer databases has deteriorated – An overview of the most important factors for each industry (excerpt)
Findings and changes compared to previous studies
- Reversal of trend: For the first time since 2018, address quality is declining again (-0.5%).
- Positive exceptions: Tourism and non-profit organizations were able to slightly improve their data quality.
- The public sector, on the other hand, has deteriorated significantly (proportion of undeliverable addresses from 13.9% to 18.2%).
Important: The number of changes in the address database continues to increase – 360,000 moves and 680,000 deaths per year alone make it clear how volatile address data can be.
Tips for everyday life – how to achieve sustainable address quality
- Regular address cleansing: At least once a year – preferably before important campaigns.
- Duplicate detection and merging: Avoids duplicate communications and saves resources.
- Use forwarding information: Particularly valuable for loyal existing customers.
Address verification during data entry: Avoid typos, e.g., through live validation in CRM or online forms.
Use customer dialogue: Use address queries as a sign of appreciation.
Address quality in customer databases has deteriorated – and here’s a very important tip:
Regular monitoring is an absolute must: Data quality is not a project, but a process.
Would you like to have the current status of your addresses validated?
Every address and data quality project we have carried out has achieved ROI within four months or significantly exceeded the ROI line.
The benefits are easy to describe, versatile, and truly enormous:
- Better-oiled processes.
- Happier employees and happier customers.
- Better reporting.
- Less money wasted.
- Better segmentation.
- AI delivers better results.
- And much more.
Conclusion:
Address quality is more than just a hygiene factor. Address and data quality are an extremely positive value-adding factor!
It directly influences costs, efficiency, customer loyalty, and ultimately the company’s image.
Especially in times of AI, hyper-personalization, and data-driven marketing, the basics of data maintenance must not be neglected. Investing in this area lays the foundation for effective CRM and CX initiatives, as well as all artificial intelligence AI initiatives.
