Frequently Asked Questions about our website and our AddressClean Services


Last Modified: 30 April 2016


Validity: We reserve the right to modify the frequently asked questions (faq) at any time. To protect your interests, visit this page periodically to know current terms.


Feedback: If you have any comments or questions on this FAQ or on any other matter, let us know by using our Contact Us page.



1. What services are provided?

We detect and optionally remove duplicates in “postal addresses” and “name & postal addresses”.

2. What output would you receive?

One of:

  • Clusters of duplicate records with a number between 0 to 100 indicating the best match in the cluster till that record – you handle subsequent removal of duplicates – see Sample result layout
  • Automatic removal of duplicates – two lists are provided – list of duplicate records removed and a list of records without duplicates
  • Removal of duplicates after examining each cluster (eyeballing) – two lists are provided – list of duplicate records removed and a list of records without duplicates – RECOMMENDED SOLUTION

3. What duplicate-detection-methods possible?

The most common are name and address, and, address. Other duplicate-detection-methods are possible – let us know your requirement and we will advise you accordingly.

5. What are the differences between one-time and on-going jobs?

A one-time job is when data is sent to us once in one or more files and one set of results are sent to you once. Three months after full & final payment all files are erased from our servers.

An on-going job is when data is sent to us from time to time and only changes are sent back. Optionally, the latest complete output is sent back every time.

6. Process flow chart for a one-time job:

AddressClean Process Flowchart

7. Process flow chart for an on-going job:

Similar to a one-time job. Will be clarified during quotation stage.

8. How to ask for a quotation?

Go to the Request quotation page and provide your name, address, country, email, contact phone, purpose, sample data of around 50 to 500 addresses, and, duplicate-detection-method (name and address, or, address – see FAQ on What duplicate-detection-methods possible). Provide the count of records in the full file. We will send you a quotation.

NOTE: The sample data will not be securely transmitted on the internet but will be handled securely by us once received.

9. What if you have multiple input data file types and/or multiple layouts?

Compress all the sample data files together and upload as a single file. Provide counts of records for each type of data file type. The compressed file should be within 100 KB in size. You will have to specify a suitable file layout & type in which the combined result data can be presented; else, we can proceed once you concur with our suggested file layout & type.


9.1. Encryption:

All results are compressed and encrypted using a pass phrase before it is transmitted to protect the data. The secure method to exchange pass phrases will be individually discussed beforehand. We request the compression and encryption of all input data (except sample data) before sending it to us. Sample data is usually not encrypted.

9.2. What is a pass phrase & how is it communicated between us?

A pass phrase is a long password that ensures more secure encryption of data. We will discuss with you after we receive your first quotation request.

9.3. How do you send us operational data and receive results?

After receiving the first advance from you, you can set up your own SFTP (Secure File Transfer Protocol) site that we can access, else, we will set up a SFTP location for you with sign-in name and password. You can upload your compressed and encrypted data and download your compressed and encrypted results from the SFTP site. Small batches of data of up to one million records can be sent both ways by email after compressing & encrypting.

9.4. Data security?

We ensure that the data will remain secure in our premises. After each job is closed, a process that overwrites all information securely erases input, result and work files. Access to the server downloading, processing and uploading your data is strictly controlled. If we set up the SFTP site then the security provided by reputed cloud services vendors shall apply and data on the SFTP site cannot be scrubbed. Also, all data at the SFTP site will be pass phrase encrypted.

We expect you to remove data from the SFTP location at your convenience. If we set up the SFTP site, files are securely erased 3 months after receipt of full payment.

9.5. You want to send the sample data securely:

Let us know using the Contact us form. We will advise you accordingly.

9.6. Personal Privacy Policy: See here.

10. Payment terms?

We start after receiving 50% advance. On completion we will advise you of run statistics and provide you with 10% of the duplicate detection result. Complete results will be provided after the remaining 50% is received.

11. Payment method?

You transfer payment directly to our bank account. Details will be given in our quotation.

12. Which countries are supported?


13. Is country information mandatory?

Yes. Country should be explicitly or implicitly specified. Each address must have country information, preferably as a separate field; else, all records must be pre-defined to belong to the same known country.

14. Are different countries handled together or separately?

The countries listed below are separated before processing and the results are delivered separately:

All Arabic countries (separately), Argentina, Australia, Belgium, Borneo, Brazil, Cambodia, Canada, Chile, China, Colombia, Czech, Denmark, Estonia, Finland, France, Germany, Greece, Hong Kong, Hungary, India, Indonesia, Ireland, Israel, Italy, Japan, Korea, Laos, Luxembourg, Malaysia, Mexico, Myanmar, Netherlands, New Zealand, Norway, Peru, Philippines, Portugal, Puerto Rico, Singapore, Slovakia, South Africa, Spain, Sweden, Switzerland, Taiwan, Thailand, Turkey, UK, USA and Vietnam.

Countries not listed above are processed together and their result is delivered together.

15. What characters are permitted in input postal address data?

All permitted characters from the Latin-1 (ISO/IEC 8859-1) set given below:

Permitted characters:

” # & ‘ ( ) , – . / 0 1 2 3 4 5 6 7 8 9 : ; A B C D E F G H I J K L M N O P Q R S T U V W X Y Z a b c d e f g h i j k l m n o p q r s t u v w x y z À Á Â Ã Ä Å Æ Ç È É Ê Ë Ì Í Î Ï Ð Ñ Ò Ó Ô Õ Ö Ø Ù Ú Û Ü Ý à á â ã ä å æ ç è é ê ë ì í î ï ð ñ ò ó ô õ ö ø ù ú û ü ý ÿ

Also, the space character is permitted.

Characters that are permitted but we suggest that their use be reviewed by you:

! $ % * + < = > ? @ [ \ ] ^ _ ` { | } ~ ¡ ¢ £ ¤ ¥ ¦ § ¨ © ª « ¬ ­ ® ¯ ° ± ² ³ ´ µ ¶ · ¸ ¹ º » ¼ ½ ¾ ¿ × Þ ß ÷ þ

Examine the list of permitted characters to see if all information can be processed. For some languages like Dutch, Finnish, French, German, Hungarian and Turkish some characters may not be in the list above. Almost always this will not be a problem. We will check each file and advise you. In rare cases a work around may be needed; such as replace a character by another set of permitted characters.

Characters that are not permitted in the data: All control characters (non printable characters).

Control characters that are not permitted in data but permitted in the file: Record separator characters such as carriage-return <CR>, line-feed <LF> or new-line “\n”. The tab character “\t” is used if the fields are tab character delimited.

16. What if other characters are detected in the input name and postal address data that cannot be processed?

We will advise you. You could opt to resend the data to us after removing; else, under your instructions, we will sanitise the data by replacing these other characters by the space character or by another set of permitted characters on your behalf. This is part of the pre-de-duplication sanitising process.

17. Why are some characters permitted but we suggest that they should not be used?

These characters usually are not part of a postal address and reduce quality of processing. We will advise you if these characters are detected and depending on your instructions will either wait for you to resend the data after removing, or, process the data as it is, or, replace the other characters by the space character on your behalf.

18. What if any field contains multiple, leading or trailing spaces?

Multiple spaces are replaced by a single space. Leading and/or trailing space are removed. We will advise you. You could opt to resend the data to us after removing extra spaces; else we will replace the extra space characters on your behalf. This is also part of the pre-de-duplication sanitising process.

19. If we sanitise the data before de-duplication, how are the results presented ?

Usually we will present the results using the sanitised data. You could opt for the result to be presented in the original form, or, with both. Presenting in pre-sanitised form or both pre & post sanitised form will incur extra charges which we will advise before hand and will wait for your approval before proceeding.

20. Data encryption & compression (zipping with pass phrase)

All results would be presented after encryption & compression as a pass phrase protected zipped file.

We request that all input be encrypted and compressed (zipped with pass phrase) before uploading or sending to us.

21. What file types of input data preferred?

Tab delimited data. CSV (comma separated variable), or, fixed layout (each field has a certain length with padding by spaces on the right), or, an Excel spread sheet may be provided.

22. What file types of input data possible?

Any other file type of your choice including XML or JSON is possible. There may be extra charges applicable, which we will advise before hand and will wait for your approval before proceeding.

23. What special precautions for CSV (comma separated variable) data?

All fields must be quoted with double apostrophes at both ends with a comma separating fields, e.g. “John Smith”,”35 Hastings Road”. Each double apostrophe within the data must be repeated, e.g. “Apollo”, 35 Hastings Road becomes “””Apollo””, 35 Hastings Road”

24. What layout & file type of result data preferred?

The layout will, as far as possible, be similar to the input you send. We would specify the layout in our quotation. There may be a cost implication if you want a different layout.

The preferred result file type is Tab delimited data.

25. What other file types of result data possible?

CSV (comma separated variable), or, fixed layout (each field has a certain length with padding by spaces on the right), or, an Excel spread sheet may be provided on your request. Any other data file type of your choice including XML or JSON is possible. There may be extra charges applicable, which we will advise before hand and will wait for your approval before proceeding.

26. Sample result layout:

A sample result layout is given below:

Cluster no.

Best match indicator within cluster till now

Record id.

Person or organisation name Address City



Jean-Jacques Martineau 14, rue de Strasbourg, ‘1100, Chalon sur Saone




Jean-Jacques Martineau 14, rue de Strasbourg, ‘1100 Chalon sur Saône



LE CROCODILE 10, rue de l’Outre, 67000 Strasbourg




Crocodil 10, rue de l’Outre

This is a simplification of one of the actual output layouts possible. We will explain when sending the first results.

27. Best results:

Obtained if the same structure is used across files & information is separated into individual fields. The next best if there is some segregation with minimum grouping, i.e. person name in one or more fields, designation, organisation, address part 1 (building, street, sub area, area), address part 2 (city, district, state, country), post code.

We can process inputs similar to a postal label layout or if the complete address appears in one string.

28. Information used for duplicate detection:

  • Identity or internal record number, e.g. national ID – MANDATORY
  • Person name – MANDATORY if individual search
  • Designation
  • Organisation
  • Address part 1 (building & street details, sub area, area) – MANDATORY
  • Address part 2 (city, district/county/canton, state, country) – MANDATORY
  • Post code – Recommended
  • Phone(s)
  • Date, e.g. birth, incorporation, marriage
  • Any two attribute fields up to 255 bytes length each

29. Multiple records for the same person:

A person can have multiple addresses, e.g. a person can have a residence and work address, or more. Or the person may have multiple phones. All these can be processed.