Solid Serial Number

What is a solid serial number?

A solid serial number is an eight-digit serial with the same digit repeated in every position. For example, 77777777 is a solid. The letters and any star are not part of the eight-digit pattern.

Solid vs near solid vs seven of a kind

Collectors and sellers use near solid inconsistently. This guide uses the exact detector labels: a solid has eight matching digits, Seven of a Kind has exactly seven, and Six of a Kind has six plus two different other digits. Seven in a Row describes position, not just the count: the seven matching digits sit together at the beginning or end. A seven-of-a-kind serial with its lone digit in the middle is not seven in a row.

Solid serial number examples and non-examples

These eight-digit strings preserve leading zeros. A solid necessarily reads the same forward and backward and repeats its first four digits as its last four, so it also matches Radar and Repeater.

How rare is a solid serial number?

There are 10 possible all-matching strings from 00000000 through 99999999 among 100,000,000 eight-digit strings, giving 1 in 10,000,000. The theoretical count includes 00000000, which is not issued as a note serial, so the circulating-note odds are not exactly the same as the full-string calculation. The hub's former 1 in 11,111,111 figure does not follow the detector rule.

99999999 is a valid mathematical solid, but it rarely circulates because normal Federal Reserve print blocks roll over before that serial. The site's serial thresholds note $1 to $20 blocks ending at 96,000,000 and $50 and $100 blocks reaching 99,200,000.

How much is a solid serial number worth?

The site's verified sold-price bands for solid notes are shown below by condition. They use modern small-size notes after excluding different markets such as star notes, silver certificates and large-size notes. Sample size and confidence are shown with each recorded band.

Compare condition and note details in the fancy serial number value guide and identify replacement notes with the star note lookup.

What raises or lowers a solid note's value?

• Digit appeal varies among collectors. A run of 7s or 8s may draw interest, while 1s can appeal for their visual simplicity; the sold bands do not break out values by digit.
• Denomination changes the face value and buyer pool, so compare notes of the same denomination.
• Condition has a large effect. Creases, stains and handling reduce eye appeal; crisp notes tend to attract more collector interest.
• A star note is a separate combination. The solid bands exclude star notes, so assess those sales separately rather than adding an assumed premium.
• The pattern overlaps with Radar and Repeater by definition, but the existing data does not isolate an added overlap premium.

Should you keep, sell, or grade a solid note?

A solid is an exceptionally unusual serial shape, so check denomination, condition and recent comparable sales before spending or selling it. Consider grading only if the note is sufficiently well preserved and likely sale proceeds justify grading, shipping and selling fees.

How to check your serial

Read all eight digits between the prefix and suffix. Confirm that each digit matches, preserve any leading zeros, then check for other patterns the same serial may match.

Use the fancy serial number checker to test the serial and see its overlapping patterns.