Paste your numbers one per line, choose the country code for numbers that start with a 0, and copy the list back in international format: 06-1234 5678 becomes +31612345678. The rules are based on the ones our CRM extension uses, and the lines stay in the same order, so you can paste the result back into your spreadsheet (format the column as Text first, see below).
Runs in your browser. Your numbers are not sent to us; we only count clicks on Copy and Download.
A wa.me link only works with it. Teams, Zoom Phone and most softphones also dial the right number when it starts with +. A number saved as 06 1234 5678 depends on the app guessing your country.
+31612345678, 06-12345678 and 0031 6 1234 5678 are the same person. Written the same way, a spreadsheet or your CRM’s duplicate check can see that.
A CRM import with mixed 06…, +31… and 0031… numbers can create three versions of one contact. Format the column first and they match.
These results come from the formatter itself, run when this page was built. The other rules (the (0) after a country code, Italy, the 0 after +44) are listed on the WhatsApp link generator page.
| You paste | Country code | You get | Why |
|---|---|---|---|
06-1234 5678 | +31 | +31612345678 | The national 0 is replaced by the country code. |
(202) 555-0123 | +1 | +12025550123 | For +1, ten digits are a full US or Canadian number. |
+32 470 12 34 56 ext. 21 | — | +32470123456 | The extension is removed; it can’t be dialled from a link. |
0031 6 1234 5678 | — | +31612345678 | 00 is the international prefix, so it becomes +. |
2025550123 | — | +2025550123 | No +, 0 or country code chosen: read as already international (+20, Egypt) and marked for checking. With +1 chosen, it becomes +12025550123. |
0612345678 | — | (empty) | Starts with 0 and no country code chosen: left empty and marked. |
Copy the phone column from your export, format it here and paste it back over the same rows. Want the original next to the result? Download the CSV.
Export your contacts, format the phone column, check the marked rows and import the file again to update the field. Test it with a few contacts first.
With clean numbers, the call buttons and the WhatsApp button in CallerPlugins never have to guess the country. For numbers that start with 0, the extension takes the country code from the first international tel: link on the CRM page, or uses +31 if there is none.
Excel and Google Sheets read +31612345678 as a number, and the + disappears. In Excel, longer numbers can also turn into 4.42079E+11. Format the column as Text (in Sheets: Plain text) before you paste. Don’t double-click the downloaded CSV: in Excel, use Data → From Text/CSV, choose Transform Data and set the column to Text, as Microsoft describes for long numbers.
The formatter rewrites numbers; it doesn’t look them up. It can’t tell whether a number exists, is a mobile number or uses WhatsApp. The result is the compact form without spaces, not the local way of writing it. A country code you choose is only used for numbers that start with a single 0 (and for ten-digit numbers with +1). One list can hold up to 5,000 lines; lines after that are ignored. The table on screen shows the first 200 numbers, so download the CSV to see the status of every row.
CallerPlugins is free for 100 clicks per tool per month for your company. See pricing.
Sources, checked 21 October 2026: ITU-T Recommendation E.164 · Microsoft Support: Keeping leading zeros and large numbers
It is free with no sign-up. The numbers are formatted in your browser and never sent to us. We only count clicks on Copy and Download.
E.164, the international numbering plan of the ITU: a +, the country code and the national number, up to 15 digits, with no spaces, brackets or national 0.
Yes, if the foreign numbers already start with + or 00. The country code you choose is only added to numbers that start with a single 0.
A marked row is too short or too long, starts with 0 while no country code is set, or has no + or 0 in front, so its first digits were taken as the country code. Fix those by hand.
Mostly. The formatter adds a few rules the extension doesn’t have. It removes extensions such as “ext. 21” and removes “(0)” after any country code except +39. It keeps the 0 in Italian numbers and adds +1 to ten-digit US and Canadian numbers. In the CRM, the extension takes the country code from the page instead of from a field.
It is a guess from your browser’s language setting. Check it before you copy, because it is added to every number that starts with 0.