HubSpot phone number format import

HubSpot recommends phone numbers in E.164 form: a leading +, country code, and up to 15 digits, with an optional extension. The safest CSV value is a complete international number rather than a local-only display format.

Common visual separators such as spaces, dots, dashes, and parentheses may be readable to humans, but they do not solve the bigger import risk when the number is missing a country code or uses a 00 prefix instead of +.

Phone validation is account-specific. A value that imports as text in one HubSpot account can be rejected or less useful in another account when phone validation is enabled or calling features expect a country code.

• Local numbers such as (555) 010-0123 do not say which country they belong to.
• International values starting with 00 are not the same shape as +15550100123.
• Mixed local formats make it harder to review whether a contacts file is ready for the destination account.

1. Decide which country each local phone value belongs to before editing the CSV.
2. Convert phone values to E.164-style text: +, country code, and the subscriber number.
3. Keep extensions explicit, for example +15550100123 ext 12.
4. Do not guess country codes for rows where the source data is ambiguous.
5. Review the destination HubSpot account's phone validation settings before committing the import.

ReadyCSV flags mapped Phone and Mobile Phone Number values with phone_format_risk when they are not E.164-shaped. This is an info-level review signal, not a blocker and not an automatic phone-number repair.

The check ignores common visual separators when a value still has a leading + and a plausible country-code shape. Values without that shape are surfaced for review before you upload to HubSpot.

ReadyCSV runs this check locally in your browser. It does not call HubSpot, validate whether a number is real, or guarantee that your destination account will accept every phone value.