Which Area Codes Are Running Out Fastest?

Rankings of US area codes by prefix utilization percentage, based on official NANPA data. Explore which area codes are closest to exhaustion and which have relief planning in progress.

330 (OH) — 98.38%— highest utilization rate
Published: Updated: Sources & Methodology

Key Findings

136
Area codes above 95% utilization
7
Currently in relief planning

US codes with utilization data. NANPA lists additional codes (e.g., Canadian, reserved overlays) in relief planning reports.

361
Area codes with utilization data

Includes US, Canadian, and special-purpose codes

The 330 area code (OH) has the highest utilization rate at 98.38%, with 787 of 800 prefixes assigned. When utilization exceeds 95%, NANPA typically begins relief planning — either an overlay or a split — to ensure continued number availability.

All Area Codes

Look up a specific area code's utilization ranking. Each row links directly to the area code's detail page.

RankArea CodeUtilization
1330
98.4%
2408
98.4%
3213
98.3%
4217
98.3%
5256
98.3%
6267
98.3%
7281
98.3%
8310
98.3%
9317
98.3%
10323
98.3%
11360
98.3%
12407
98.3%
13469
98.3%
14470
98.3%
15484
98.3%
16540
98.3%
17561
98.3%
18573
98.3%
19618
98.3%
20702
98.3%
21713
98.3%
22714
98.3%
23740
98.3%
24786
98.3%
25805
98.3%
26815
98.3%
27832
98.3%
28847
98.3%
29909
98.3%
30205
98.1%
31208
98.1%
32214
98.1%
33240
98.1%
34248
98.1%
35304
98.1%
36305
98.1%
37312
98.1%
38415
98.1%
39443
98.1%
40510
98.1%
41512
98.1%
42608
98.1%
43619
98.1%
44678
98.1%
45707
98.1%
46715
98.1%
47720
98.1%
48757
98.1%
49760
98.1%
50773
98.1%
51812
98.1%
52816
98.1%
53850
98.1%
54870
98.1%
55904
98.1%
56910
98.1%
57916
98.1%
58972
98.1%
59202
98.0%
60203
98.0%
61209
98.0%
62210
98.0%
63212
98.0%
64301
98.0%
65303
98.0%
66309
98.0%
67334
98.0%
68347
98.0%
69404
98.0%
70503
98.0%
71513
98.0%
72516
98.0%
73630
98.0%
74717
98.0%
75770
98.0%
76803
98.0%
77814
98.0%
78864
98.0%
79917
98.0%
80920
98.0%
81215
97.9%
82314
97.9%
83336
97.9%
84405
97.9%
85410
97.9%
86419
97.9%
87601
97.9%
88708
97.9%
89724
97.9%
90801
97.9%
91813
97.9%
92843
97.9%
93845
97.9%
94402
97.8%
95480
97.8%
96541
97.8%
97610
97.8%
98631
97.8%
99704
97.8%
100817
97.8%
101818
97.8%
102860
97.8%
103918
97.8%
104315
97.6%
105559
97.6%
106570
97.6%
107646
97.6%
108804
97.6%
109919
97.6%
110530
97.5%
111609
97.5%
112615
97.5%
113937
97.5%
114718
97.4%
115732
97.4%
116201
97.3%
117614
97.3%
118706
97.1%
119787
97.1%
120973
97.1%
121954
97.0%
122518
96.9%
123703
96.9%
124978
96.6%
125970
96.5%
126903
96.4%
127270
96.3%
128313
96.1%
129781
96.1%
130617
96.0%
131716
95.6%
132318
95.5%
133507
95.4%
134412
95.3%
135423
95.3%
136509
95.1%
137440
94.8%
138662
94.4%
139406
94.3%
140206
94.1%
141603
94.0%
142602
93.5%
143508
93.4%
144605
93.1%
145346
93.0%
146701
92.9%
147949
92.9%
148207
92.8%
149580
92.4%
150626
91.8%

Showing 150 of 361 area codes

Methodology

Data sources: Prefix utilization data from the NANPA NPA Exhaust Analysis report. Relief planning status from the NANPA NPA Relief Planning Reports.

Utilization %: Calculated as (assigned prefixes / total assignable prefixes) × 100. Only prefixes marked as "assigned" in the NANPA database are counted.

Ranking: Area codes are sorted by utilization percentage (descending), with ties broken by total assigned prefixes.

Excluded: 15 recently activated or pending overlay area codes (no utilization data yet) with 0% utilization (assigned but not yet active) are not listed here. See the Statistics page for the full list of reserved codes.

Last updated: September 8, 2026

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