Historical area-number reference

Social Security Number Prefixes for Delaware

The historical area-number ranges listed for Delaware are 221-222.

Historical cutoff: June 25, 2011 · Reference reviewed: 2026-09-12

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Area-number ranges1listed ranges
Lowest listed area221historical
Highest listed area222historical
Area numbers listed2across the ranges
Historical only: These ranges do not prove birthplace, current residence, address or identity. They do not apply to new SSNs assigned after June 25, 2011.

Plain-language answer

What Delaware prefixes mean

Before June 25, 2011, an older SSN beginning with an area number in the ranges below was associated with Delaware in the historical assignment record, usually through the mailing address on the original application.

For example, an old number beginning with 221 may fit this historical Delaware area-number record. This does not identify a person and does not show where the person lives now.

Listed ranges

Delaware area-number ranges

Historical Delaware area-number ranges before June 25, 2011
Area-number rangeCount of area numbers
221–2222

Know the limit

Why newer numbers are different

Randomization ended the geographic connection for new numbers. The first three digits of a newer SSN cannot reliably tell you a state or territory.

This page is an educational historical reference. It is not an identity lookup, background check or current-location search.

Quick answers

Delaware SSN prefix FAQs

What are the Social Security number prefixes for Delaware?

The historical area-number ranges listed for Delaware are 221-222. These ranges apply only to older numbers issued before June 25, 2011.

Does a Delaware prefix show where someone lives?

No. A historical prefix was generally tied to the mailing address on the original application, not a current address, birthplace or identity.

Do these prefixes apply to newer SSNs?

No. Since June 25, 2011, new numbers have been assigned randomly and the first three digits no longer have geographic meaning.

Can this page identify a person?

No. A prefix is only a historical reference. It cannot confirm who owns a number or identify a person.