Telephone numbering plan
Numbering plan indicator
The numbering plan indicator (NPI) is a number which is defined in the ITU standard Q.713, paragraph 3.4.2.3.3, indicating the numbering plan of the attached telephone number.

Telephone numbering plan

Section Title: Numbering plan indicator
Table Section Text: The numbering plan indicator (NPI) is a number which is defined in the ITU standard Q.713, paragraph 3.4.2.3.3, indicating the numbering plan of the attached telephone number.

NPI	Description	Standard

0	unknown

1	ISDN Telephony	E.164

2	generic

3	data	X.121

4	telex	F69

5	maritime mobile	E.210 and E.211

6	land mobile	E.212

7	ISDN/mobile	E.214

Sentence(s)

The E.164 standard of the International Telecommunications Union is a numbering plan.
The E.164 standard is an international numbering plan.
The E.164 standard of the International Telecommunications Union is an international numbering plan.

final_sentence: The E.164 standard of the International Telecommunications Union is a numbering plan.
final_sentence: The E.164 standard is an international numbering plan.
final_sentence: The E.164 standard of the International Telecommunications Union is an international numbering plan.