All assignees
382 prefixes in 857 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 857-200 | BOSTON | 6387 | 2011-01-10 | Yes |
| 857-201 | WINTHROP | 5562 | 2002-10-28 | Yes |
| 857-202 | BOSTON | 6387 | 2011-11-10 | Yes |
| 857-203 | JAMAICA PL | 9102 | 2005-02-28 | Yes |
| 857-204 | BOSTON | 6889 | 2001-03-20 | Yes |
| 857-205 | BOSTON | 4036 | 2001-03-19 | — |
| 857-206 | BOSTON | 6387 | 2011-10-07 | Yes |
| 857-207 | BOSTON | 6387 | 2007-04-11 | Yes |
| 857-208 | BOSTON | 6387 | 2012-02-08 | Yes |
| 857-209 | CAMBRIDGE | 4018 | 2001-10-11 | Yes |
| 857-210 | BOSTON | 6889 | 2011-03-10 | Yes |
| 857-211 | XXXXXXXXXX | MULT | — | — |
| 857-212 | DORCHESTER | 5562 | 2001-04-23 | Yes |
| 857-213 | BOSTON | 829J | 2011-10-03 | Yes |
| 857-214 | BOSTON | 6387 | 2011-12-06 | Yes |
| 857-215 | BROOKLINE | 9102 | 2010-02-23 | Yes |
| 857-216 | NEWTON | 316E | 2009-11-03 | Yes |
| 857-217 | DORCHESTER | 5562 | 2001-06-29 | Yes |
| 857-218 | BROOKLINE | 9102 | 2007-01-12 | Yes |
| 857-219 | NEWTON | 892D | 2012-02-16 | Yes |
| 857-220 | DORCHESTER | 829J | 2001-03-20 | Yes |
| 857-221 | BOSTON | 5562 | 2005-05-25 | Yes |
| 857-222 | BOSTON | 6889 | 2001-05-17 | — |
| 857-223 | BOSTON | 829J | — | Yes |
| 857-224 | BOSTON | 9102 | 2009-12-17 | Yes |
| 857-225 | BROOKLINE | 6387 | 2001-05-03 | Yes |
| 857-226 | NEWTON | 671J | 2006-03-30 | Yes |
| 857-227 | SOMERVILLE | 7229 | 2001-05-23 | Yes |
| 857-228 | WATERTOWN | 829J | 2001-07-12 | Yes |
| 857-229 | NEWTON | 829J | — | Yes |
| 857-230 | ROXBURY | 6889 | 2009-04-15 | Yes |
| 857-231 | NEWTON | 5562 | 2002-07-30 | Yes |
| 857-232 | NEWTON | 892D | 2006-05-17 | Yes |
| 857-233 | BOSTON | 6889 | 2006-02-16 | Yes |
| 857-234 | BROOKLINE | 6889 | 2002-03-18 | Yes |
| 857-235 | CAMBRIDGE | 9102 | 2008-11-18 | Yes |
| 857-236 | BOSTON | 5562 | 2008-08-04 | Yes |
| 857-237 | BOSTON | 5562 | 2009-06-08 | Yes |
| 857-238 | BOSTON | 9102 | 2007-11-14 | Yes |
| 857-239 | BOSTON | 892D | — | Yes |
| 857-240 | NEWTON | 268F | 2012-02-28 | Yes |
| 857-241 | BOSTON | 4018 | 2006-10-24 | Yes |
| 857-242 | CAMBRIDGE | 671J | 2011-09-08 | Yes |
| 857-243 | BOSTON | 892D | 2009-11-05 | Yes |
| 857-244 | BOSTON | 990E | 2008-06-10 | Yes |
| 857-245 | BROOKLINE | 316E | 2006-11-02 | Yes |
| 857-246 | BOSTON | 5562 | — | Yes |
| 857-247 | BOSTON | 5562 | 2009-06-08 | Yes |
| 857-248 | BOSTON | 6387 | 2012-03-08 | Yes |
| 857-249 | BOSTON | 5562 | 2008-08-04 | Yes |
| 857-250 | BOSTON | 6889 | 2011-07-15 | Yes |
| 857-251 | BOSTON | 5562 | 2008-08-04 | Yes |
| 857-252 | QUINCY | 829J | 2001-04-23 | Yes |
| 857-253 | CAMBRIDGE | 829J | 2001-04-23 | Yes |
| 857-254 | BOSTON | 829J | 2001-04-23 | Yes |
| 857-255 | NEWTON | 829J | 2001-04-23 | Yes |
| 857-256 | EASTBOSTON | 268F | 2011-11-24 | Yes |
| 857-257 | SO BOSTON | 5562 | 2001-04-20 | Yes |
| 857-258 | BOSTON | 5562 | 2010-06-25 | Yes |
| 857-259 | CAMBRIDGE | 4036 | 2011-05-24 | Yes |
| 857-260 | BOSTON | 6387 | 2012-03-08 | Yes |
| 857-261 | BOSTON | 5562 | 2011-02-22 | Yes |
| 857-262 | BOSTON | 6387 | 2015-09-03 | Yes |
| 857-263 | BOSTON | 6387 | 2011-07-12 | Yes |
| 857-264 | BOSTON | 6889 | 2010-09-21 | Yes |
| 857-265 | BOSTON | 4036 | 2011-07-12 | Yes |
| 857-266 | BOSTON | 5562 | 2010-06-10 | Yes |
| 857-267 | MILTON | 318J | 2013-07-15 | Yes |
| 857-268 | BOSTON | 6387 | 2011-09-08 | Yes |
| 857-269 | ROXBURY | 268F | 2013-04-24 | Yes |
| 857-270 | CAMBRIDGE | 6387 | 2014-09-30 | Yes |
| 857-271 | DORCHESTER | 892D | — | Yes |
| 857-272 | BOSTON | 4036 | 2006-03-01 | Yes |
| 857-273 | JAMAICA PL | 318J | 2013-04-23 | Yes |
| 857-274 | BOSTON | 6387 | 2016-01-29 | Yes |
| 857-275 | BOSTON | 6387 | 2015-07-01 | Yes |
| 857-276 | BOSTON | 6387 | 2015-08-17 | Yes |
| 857-277 | BOSTON | 6889 | 2006-01-03 | Yes |
| 857-278 | BOSTON | 6387 | 2015-07-01 | Yes |
| 857-279 | NEWTON | 6387 | 2016-01-29 | Yes |
| 857-280 | BRIGHTON | 892D | 2016-02-26 | Yes |
| 857-281 | QUINCY | 6387 | 2020-08-19 | Yes |
| 857-282 | BOSTON | 9102 | 2015-11-04 | Yes |
| 857-283 | BOSTON | 6387 | 2017-04-27 | Yes |
| 857-284 | BOSTON | 6889 | 2008-01-15 | Yes |
| 857-285 | CAMBRIDGE | 829J | 2012-08-16 | Yes |
| 857-286 | BOSTON | 6387 | 2017-04-28 | Yes |
| 857-287 | BOSTON | 5562 | 2017-01-31 | Yes |
| 857-288 | BOSTON | 7229 | 2006-08-01 | Yes |
| 857-289 | BOSTON | 892D | 2017-05-01 | Yes |
| 857-290 | NEWTON | 6387 | 2017-05-16 | Yes |
| 857-291 | BOSTON | 6387 | 2017-08-07 | Yes |
| 857-292 | BOSTON | 6387 | 2017-08-08 | Yes |
| 857-293 | EASTBOSTON | 829J | 2010-02-15 | Yes |
| 857-294 | BOSTON | 6387 | 2007-05-11 | Yes |
| 857-295 | BOSTON | 6387 | 2017-08-08 | Yes |
| 857-296 | BOSTON | 4018 | 2017-08-16 | Yes |
| 857-297 | NEWTON | 318J | 2017-08-22 | Yes |
| 857-298 | CAMBRIDGE | 624H | 2017-09-22 | Yes |
| 857-299 | BELMONT | 892D | — | Yes |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.