---
kind: "section"
citation: "14 C.F.R. § 45.21"
title: "14"
number: "45.21"
heading: "General."
url: "https://uscodex.org/cfr/14/45.21"
---

# §45.21. General.

- (a) Except as provided in [§ 45.22](/cfr/14/45.22.md), no person may operate a U.S.-registered aircraft unless that aircraft displays nationality and registration marks in accordance with the requirements of this section and [§§ 45.23 through 45.33](/cfr/14/45.23..45.33.md).
- (b) Unless otherwise authorized by the FAA, no person may place on any aircraft a design, mark, or symbol that modifies or confuses the nationality and registration marks.
- (c) **Aircraft nationality and registration marks must—**
  - (1) Except as provided in [paragraph (d)](#d) of this section, be painted on the aircraft or affixed by any other means insuring a similar degree of permanence;
  - (2) Have no ornamentation;
  - (3) Contrast in color with the background; and
  - (4) **Be legible.**
- (d) The aircraft nationality and registration marks may be affixed to an aircraft with readily removable material if—
  - (1) It is intended for immediate delivery to a foreign purchaser;
  - (2) It is bearing a temporary registration number; or
  - (3) It is marked temporarily to meet the requirements of [§ 45.22(c)(1)](/cfr/14/45.22.md?p=c-1) or [§ 45.29(h)](/cfr/14/45.29.md?p=h) of this part, or both.

## Notes

### Amendments

[Doc. No. 8093, Amdt. 45-5, 33 FR 450, Jan. 12, 1968, as amended by Amdt. 45-17, 52 FR 34102, Sept. 9, 1987]

### Authority

Authority: 49 U.S.C. 106(f), 40103, 40113-40114, 44101-44105, 44107-44111, 44504, 44701, 44708-44709, 44711-44713, 44725, 45302-45303, 46104, 46304, 46306, 47122.

### Source

Source: Docket No. 2047, 29 FR 3223, Mar. 11, 1964, unless otherwise noted.

### Amendments

[Doc. No. 8093, Amdt. 45-5, 33 FR 450, Jan. 12, 1968, as amended by Amdt. 45-17, 52 FR 34102, Sept. 9, 1987]