Why phone format matters
Phone numbers are one of the trickiest data types to handle. There's no universal format. A customer might enter (555) 123-4567, another enters 555-123-4567, and another enters 5551234567 or +1 555 123 4567. All represent the same number, but in different formats.
Validation fails
If your system expects one format and gets another, validation fails. The import rejects valid phone numbers because they don't match the expected pattern.
International numbers break
US numbers use one format, UK uses another, Australia another. A CSV with mixed international numbers will have inconsistent formatting.
Duplicates aren't detected
The same person's number in two formats (555-123-4567 and 5551234567) looks like different numbers. Deduplication fails.
SMS/calling fails
Systems that send SMS or make calls need a consistent format. Extra characters, spaces, or dashes can break the integration.
The problem in action:
What users enter
(555) 123-4567 555-123-4567 5551234567 +1 (555) 123-4567
What your system needs
5551234567 5551234567 5551234567 15551234567
The solution: Standardize phone numbers before importing. Strip formatting, remove spaces and dashes, keep only digits (plus country code if needed).
Common phone number formats
Here are the formats you'll see most often:
(XXX) XXX-XXXX
North America
Example:
(555) 123-4567Stripped to digits:
5551234567XXX-XXX-XXXX
North America
Example:
555-123-4567Stripped to digits:
5551234567XXXXXXXXXX
North America
Example:
5551234567Stripped to digits:
5551234567+1 (XXX) XXX-XXXX
International
Example:
+1 (555) 123-4567Stripped to digits:
15551234567+44 XXXX XXX XXX
UK
Example:
+44 1234 567 890Stripped to digits:
441234567890+61 X XXXX XXXX
Australia
Example:
+61 2 1234 5678Stripped to digits:
61212345678How to standardize phone numbers
The safest approach: strip everything except digits (and the leading + if it's an international number), then store the pure digit version.
Simple standardization rule:
- 1Remove all spaces, dashes, parentheses, and dots
- 2Keep only digits and the leading + (if present)
- 3Remove the leading + before storing (unless you need to preserve country codes)
- 4For US/Canada numbers, remove leading 1 if you want just the 10-digit number
Examples:
International phone numbers
International numbers are more complex because they use different lengths and country codes. The key: always include the country code in your standardized format.
Best practice for international numbers:
Store as: +CC (country code)NNNNNNNNN (local number with no formatting)
United States:
Input: (555) 123-4567 | Stored: +15551234567
UK:
Input: +44 1234 567 890 | Stored: +441234567890
Australia:
Input: +61 2 1234 5678 | Stored: +61212345678
Important:
If your CSV has mixed international numbers, you MUST include country codes. If all numbers are from one country, you can standardize to just the local format (10 digits for US), but document this clearly so there's no confusion later.
Phone number best practices
Collect clean phone data
Import Builder phone columns accept any common layout and flag what can't be a phone number (letters, Excel's scientific notation, too few or too many digits) as people enter it.
Start building free