This overview lists flags used by first-level country subdivisions. The status of these flags varies from one country or sovereign state to the next: most of them are official flags, whereas others are only used de facto, sometimes to indicate a desire for more autonomy or independence.
Flag of Bosnia and Herzegovina
Flag of Central African Republic
Flag of Democratic Republic of the Congo
All of these flags are fictitious or only proposed, check this.
Flag of Federated States of Micronesia
Flag of Saint Vincent and the Grenadines