Accession Number prefixes: Where did the data originate?

The International Nucleotide Sequence Database Collaboration (INSDC) is a long-standing foundational initiative that operates between DDBJ, EBI and NCBI. Each member receives sequence submissions, assigns accession numbers, and exchanges data so that all three groups represent the total collection. The accession assignment process is managed within the collaboration to ensure accession numbers are unique by allotting accession prefixes to individual members. This list of accession number prefixes should be used as a guide to the type of record and the INSDC member to which the record was submitted. There are rare cases where these assignments are not strictly obeyed, for example, there are ESTs from NCBI with a Direct submissions prefix

INSDC Accession Prefix Format

The format for Accession numbers is:

Nucleotide:
       1 letter + 5 digits
       2 letters + 6 digits
       2 letters + 8 digits

Protein:     
       3 letters + 5 digits
       3 letters + 7 digits

WGS/TSA/TLS:   
       4 letters + 2 digits for assembly version + 6 or more digits
       6 letters + 2 digits for assembly version + 7 or more digits

SRA (Sequence Read Archive):
       3 letters (see prefix below) + 6 or more digits

BioSample:
       4 letters (see prefix below) + 8 or more digits

BioProject:
       5 letters (see prefix below) + 1 or more digits

MGA:           
       5 letters + 7 digits

Accession Prefix	INSDC Partner	Sequence Type	Accession Format
A	EBI	Patent	1+5
AA	NCBI	EST	2+6
AAA-AZZ	NCBI	protein	3+5 and 3+7
AAAA-AZZZ	NCBI	WGS	4+8 or more
AAAAA-AZZZZ	DDBJ	MGA	5+7
AAAAAA-AZZZZZ	NCBI	WGS	6+9 or more
AB	DDBJ	Direct submissions	2+6
AC	NCBI	HTG	2+6
AD	NCBI	Seqs received at GSDB	2+6
AE	NCBI	Genome projects	2+6
AF	NCBI	Direct submissions	2+6
AG	DDBJ	GSS	2+6
AH	NCBI	Direct submissions segsets	2+6
AI	NCBI	Other projects	2+6
AJ	EBI	Direct submissions	2+6
AK	DDBJ	HTC	2+6
AL	EBI	Genome projects	2+6
AM	EBI	Direct submissions	2+6
AN	EBI	scaffold/CON	2+6
AP	DDBJ	Genome projects	2+6
AQ	NCBI	GSS	2+6
AR	NCBI	Patent	2+6
AS	NCBI	Other projects	2+6
AT	DDBJ	EST	2+6
AU	DDBJ	EST	2+6
AV	DDBJ	EST	2+6
AW	NCBI	EST	2+6
AX	EBI	Patent	2+6
AY	NCBI	Direct submissions	2+6
AZ	NCBI	GSS	2+6
B	NCBI	GSS (previously DDBJ)	1+5
BA	DDBJ	scaffold/CON	2+6
BAA-BZZ	DDBJ	protein	3+5 and 3+7
BAAA-BZZZ	DDBJ	WGS	4+8 or more
BAAAAA-BZZZZZ	DDBJ	WGS	6+9 or more
BB	DDBJ	EST	2+6
BC	NCBI	cDNA project	2+6
BD	DDBJ	Patent	2+6
BE	NCBI	EST	2+6
BF	NCBI	EST	2+6
BG	NCBI	EST	2+6
BH	NCBI	GSS	2+6
BI	NCBI	EST	2+6
BJ	DDBJ	EST	2+6
BK	NCBI	TPA	2+6
BL	NCBI	TPA CON	2+6
BM	NCBI	EST	2+6
BN	EBI	TPA	2+6
BP	DDBJ	EST	2+6
BQ	NCBI	EST	2+6
BR	DDBJ	TPA	2+6
BS	DDBJ	Genome projects	2+6
BT	NCBI	FLI_cDNA	2+6
BU	NCBI	EST	2+6
BV	NCBI	STS	2+6
BW	DDBJ	EST	2+6
BX	EBI	Genome projects	2+6
BY	DDBJ	EST	2+6
BZ	NCBI	GSS	2+6
C	DDBJ	EST	1+5
CA	NCBI	EST	2+6
CAA-CZZ	EBI	protein	3+5 and 3+7
CAAA-CZZZ	EBI	WGS	4+8 or more
CAAAAA-CZZZZZ	EBI	WGS	6+9 or more
CB	NCBI	EST	2+6
CC	NCBI	GSS	2+6
CD	NCBI	EST	2+6
CE	NCBI	GSS	2+6
CF	NCBI	EST	2+6
CG	NCBI	GSS	2+6
CH	NCBI	scaffold/CON	2+6
CI	DDBJ	EST	2+6
CJ	DDBJ	EST	2+6
CK	NCBI	EST	2+6
CL	NCBI	GSS	2+6
CM	NCBI	scaffold/CON	2+6
CN	NCBI	EST	2+6
CO	NCBI	EST	2+6
CP	NCBI	Genome projects	2+6
CQ	EBI	Patent	2+6
CR	EBI	Genome projects	2+6
CS	EBI	Patent	2+6
CT	EBI	Genome projects	2+6
CU	EBI	Genome projects	2+6
CV	NCBI	EST	2+6
CW	NCBI	GSS	2+6
CX	NCBI	EST	2+6
CY	NCBI	Influenza Virus Genome	2+6
CZ	NCBI	GSS	2+6
D	DDBJ	Direct submissions	1+5
DA	DDBJ	EST	2+6
DAA-DZZ	NCBI	TPA or TPA WGS protein	3+5 and 3+7
DAAA-DZZZ	NCBI	WGS/TSA/TLS TPA	4+8 or more
DAAAAA-DZZZZZ	NCBI	WGS/TSA/TLS TPA	6+9 or more
DB	DDBJ	EST	2+6
DC	DDBJ	EST	2+6
DD	DDBJ	Patent	2+6
DE	DDBJ	GSS	2+6
DF	DDBJ	scaffold/CON	2+6
DG	DDBJ	scaffold/CON	2+6
DH	DDBJ	GSS	2+6
DI	DDBJ	Patent KIPO	2+6
DJ	DDBJ	Patent JPO	2+6
DK	DDBJ	EST	2+6
DL	DDBJ	Patent JPO	2+6
DM	DDBJ	Patent JPO	2+6
DN	NCBI	EST	2+6
DO	NCBI	not used	2+6
DP	NCBI	HTG scaffolds (CONs)	2+6
DQ	NCBI	Direct submissions	2+6
DR	NCBI	EST	2+6
DRA	DDBJ	SRA submissions	3+6 or more
DRP	DDBJ	SRA sample	3+6 or more
DRR	DDBJ	SRA runs	3+6 or more
DRX	DDBJ	SRA experiment	3+6 or more
DRZ	DDBJ	SRA analysis object	3+6 or more
DS	NCBI	scaffold/CON	2+6
DT	NCBI	EST	2+6
DU	NCBI	GSS	2+6
DV	NCBI	EST	2+6
DW	NCBI	EST	2+6
DX	NCBI	GSS	2+6
DY	NCBI	EST	2+6
DZ	NCBI	Patent	2+6
E	DDBJ	Patent	1+5
EA	NCBI	Patent	2+6
EAA-EZZ	NCBI	WGS protein	3+5 and 3+7
EAAA-EZZZ	DDBJ	WGS TPA	4+8 or more
EB	NCBI	EST	2+6
EC	NCBI	EST	2+6
ED	NCBI	GSS	2+6
EE	NCBI	EST	2+6
EF	NCBI	Direct submissions	2+6
EG	NCBI	EST	2+6
EH	NCBI	EST	2+6
EI	NCBI	GSS	2+6
EJ	NCBI	GSS	2+6
EK	NCBI	GSS	2+6
EL	NCBI	EST	2+6
EM	NCBI	scaffold/CON	2+6
EN	NCBI	scaffold/CON	2+6
EO	NCBI	not used
EP	NCBI	scaffold/CON	2+6
EQ	NCBI	scaffold/CON	2+6
ER	NCBI	GSS	2+6
ERA	EBI	SRA submissions	3+6 or more
ERP	EBI	SRA sample	3+6 or more
ERR	EBI	SRA runs	3+6 or more
ERX	EBI	SRA experiment	3+6 or more
ERZ	EBI	SRA analysis object	3+6 or more
ES	NCBI	EST	2+6
ET	NCBI	GSS	2+6
EU	NCBI	Direct submissions	2+6
EV	NCBI	EST	2+6
EW	NCBI	EST	2+6
EX	NCBI	EST	2+6
EY	NCBI	EST	2+6
EZ	NCBI	TSA	2+6
F	EBI	EST	1+5
FA	NCBI	scaffold/CON (pseudomolecules)	2+6
FAA-FZZ	DDBJ	TPA protein	3+5
FAAA-FZZZ	EBI	WGS	4+8 or more
FB	EBI	Patent	2+6
FC	NCBI	EST	2+6
FD	NCBI	EST	2+6
FE	NCBI	EST	2+6
FF	NCBI	EST	2+6
FG	NCBI	EST	2+6
FH	NCBI	GSS	2+6
FI	NCBI	GSS	2+6
FJ	NCBI	Direct submissions	2+6
FK	NCBI	EST	2+6
FL	NCBI	EST	2+6
FM	EBI	Direct submissions	2+6
FN	EBI	Direct submissions	2+6
FO	EBI	Direct submissions	2+6
FP	EBI	Direct submissions	2+6
FQ	EBI	Direct submissions	2+6
FR	EBI	Direct submissions	2+6
FS	DDBJ	EST	2+6
FT	DDBJ	GSS	2+6
FU	DDBJ	Patent	2+6
FV	DDBJ	Patent JPO	2+6
FW	DDBJ	Patent	2+6
FX	DDBJ	TSA	2+6
FY	DDBJ	EST	2+6
FZ	DDBJ	Patent	2+6
G	NCBI	STS	1+5
GA	DDBJ	GSS	2+6
GAA-GZZ	DDBJ	WGS protein	3+5
GAAA-GZZZ	NCBI	TSA	4+8 or more
GB	DDBJ	Patent JPO	2+6
GC	NCBI	Patent	2+6
GD	NCBI	EST	2+6
GE	NCBI	EST	2+6
GF	NCBI	STS	2+6
GG	NCBI	scaffold/CON	2+6
GH	NCBI	EST	2+6
GI	NCBI	not used
GJ	NCBI	TPA CON	2+6
GK	NCBI	TPA CON (WGS chromosomes)	2+6
GL	NCBI	scaffold/CON	2+6
GM	EBI	Patent	2+6
GN	EBI	Patent	2+6
GO	NCBI	EST	2+6
GP	NCBI	Patent	2+6
GQ	NCBI	Direct submissions	2+6
GR	NCBI	EST	2+6
GS	NCBI	GSS	2+6
GT	NCBI	EST	2+6
GU	NCBI	Direct submissions	2+6
GV	NCBI	Patent	2+6
GW	NCBI	EST	2+6
GX	NCBI	Patent	2+6
GY	NCBI	Patent	2+6
GZ	NCBI	Patent	2+6
H	NCBI	EST	1+5
HA	EBI	Patent	2+6
HAA-HZZ	NCBI	WGS/TSA TPA protein	3+5 and 3+7
HAAA-HZZZ	EBI	TSA	4+8 or more
HB	EBI	Patent	2+6
HC	EBI	Patent	2+6
HD	EBI	Patent	2+6
HE	EBI	Direct submissions	2+6
HF	EBI	Direct submissions	2+6
HG	EBI	Direct submissions	2+6
HH	EBI	Patent	2+6
HI	EBI	Patent	2+6
HJ	NCBI	Patent	2+6
HK	NCBI	Patent	2+6
HL	NCBI	Patent	2+6
HM	NCBI	Direct submissions	2+6
HN	NCBI	GSS	2+6
HO	NCBI	EST	2+6
HP	NCBI	TSA	2+6
HQ	NCBI	Direct submissions	2+6
HR	NCBI	GSS	2+6
HS	NCBI	EST	2+6
HT	DDBJ	TPA CON	2+6
HU	DDBJ	TPA CON	2+6
HV	DDBJ	Patent JPO	2+6
HW	DDBJ	Patent JPO	2+6
HX	DDBJ	EST	2+6
HY	DDBJ	EST	2+6
HZ	DDBJ	Patent JPO	2+6
I	NCBI	Patent	1+5
IAA-IZZ	DDBJ	TPA WGS protein	3+5
IAAA-IZZZ	DDBJ	TSA	4+8 or more
J	NCBI	LANL Direct submissions	1+5
JA	EBI	Patent	2+6
JAA-JZZ	NCBI	TSA protein	3+5
JAAA-JZZZ	NCBI	WGS	4+8 or more
JAAAAA-JZZZZZ	NCBI	WGS	6+9 or more
JB	EBI	Patent	2+6
JC	EBI	Patent	2+6
JD	EBI	Patent	2+6
JE	EBI	Patent	2+6
JF	NCBI	Direct submissions	2+6
JG	NCBI	EST	2+6
JH	NCBI	scaffold/CON	2+6
JI	NCBI	TSA	2+6
JJ	NCBI	GSS	2+6
JK	NCBI	EST	2+6
JL	NCBI	TSA	2+6
JM	NCBI	GSS	2+6
JN	NCBI	Direct submissions	2+6
JO	NCBI	TSA	2+6
JP	NCBI	TSA	2+6
JQ	NCBI	Direct submissions	2+6
JR	NCBI	TSA	2+6
JS	NCBI	GSS	2+6
JT	NCBI	TSA	2+6
JU	NCBI	TSA	2+6
JV	NCBI	TSA	2+6
JW	NCBI	TSA	2+6
JX	NCBI	Direct submissions	2+6
JY	NCBI	GSS	2+6
JZ	NCBI	EST	2+6
K	NCBI	LANL Direct submissions	1+5
KA	NCBI	TSA	2+6
KAA-KZZ	NCBI	WGS protein	3+5 and 3+7
KAAA-KZZZ	NCBI	TLS	4+8 or more
KB	NCBI	scaffold/CON	2+6
KC	NCBI	Direct submissions	2+6
KD	NCBI	scaffold/CON	2+6
KE	NCBI	scaffold/CON	2+6
KF	NCBI	Direct submissions	2+6
KG	NCBI	GSS	2+6
KH	NCBI	Patent	2+6
KI	NCBI	scaffold/CON	2+6
KJ	NCBI	Direct submissions	2+6
KK	NCBI	scaffold/CON	2+6
KL	NCBI	scaffold/CON	2+6
KM	NCBI	Direct submissions	2+6
KN	NCBI	scaffold/CON	2+6
KO	NCBI	GSS	2+6
KP	NCBI	Direct submissions	2+6
KQ	NCBI	scaffold/CON	2+6
KR	NCBI	Direct submissions	2+6
KS	NCBI	GSS	2+6
KT	NCBI	Direct submissions	2+6
KU	NCBI	Direct submissions	2+6
KV	NCBI	scaffold/CON	2+6
KX	NCBI	Direct submissions	2+6
KY	NCBI	Direct submissions	2+6
KZ	NCBI	scaffold/CON	2+6
L	NCBI	LANL Direct submissions	1+5
LA	DDBJ	TSA	2+6
LAA-LZZ	DDBJ	TSA/TLS protein	3+5
LAAA-LZZZ	NCBI	WGS	4+8 or more
LB	DDBJ	GSS	2+6
LC	DDBJ	Direct submissions	2+6
LD	DDBJ	scaffold/CON	2+6
LE	DDBJ	TSA	2+6
LF	DDBJ	Patent	2+6
LG	DDBJ	Patent	2+6
LH	DDBJ	TSA	2+6
LI	DDBJ	TSA	2+6
LJ	DDBJ	TSA	2+6
LK	EBI	Direct submissions	2+6
LL	EBI	Direct submissions	2+6
LM	EBI	Direct submissions	2+6
LN	EBI	Direct submissions	2+6
LO	EBI	Direct submissions	2+6
LP	EBI	Patent	2+6
LQ	EBI	Patent	2+6
LR	EBI	Direct submissions	2+6
LS	EBI	Direct submissions	2+6
LT	EBI	Direct submissions	2+6
LU	DDBJ	EST	2+6
LV	DDBJ	Patent	2+6
LX	DDBJ	Patent	2+6
LY	DDBJ	Patent	2+6
LZ	DDBJ	Patent	2+6
M	NCBI	LANL Direct submissions	1+5
MA	DDBJ	Patent	2+6
MAA-MZZ	NCBI	WGS/TSA protein	3+5 and 3+7
MAAA-MZZZ	NCBI	WGS	4+8 or more
MB	DDBJ	Patent	2+6
MC	DDBJ	Patent	2+6
MD	DDBJ	Patent	2+6
ME	DDBJ	Patent	2+6
MF	NCBI	Direct submissions	2+6
MG	NCBI	Direct submissions	2+6
MH	NCBI	Direct submissions	2+6
MI	NCBI	Patent	2+6
MJ	NCBI	GSS	2+6
MK	NCBI	Direct submissions	2+6
ML	NCBI	scaffold/CON	2+6
MM	NCBI	Patent	2+6
MN	NCBI	Direct submissions	2+6
MO	NCBI	Patent	2+6
MP	EBI	Patent	2+6
MQ	EBI	Patent	2+6
MR	EBI	Patent	2+6
MS	EBI	Patent	2+6
MT	NCBI	Direct submissions	2+6
MU	NCBI	scaffold/CON	2+6
MV	NCBI	Patent	2+6
MW	NCBI	Direct submissions	2+6
MX	NCBI	Patent	2+6
MY	NCBI	Patent	2+6
MZ	NCBI	Direct submissions	2+6
N	NCBI	EST	1+5
NAA-NZZ	NCBI	WGS/TSA protein	3+5
NAAA-NZZZ	NCBI	WGS	4+8 or more
OA	EBI	Direct submissions	2+6
OAA-OZZ	NCBI	WGS protein	3+5
OAAA-OZZZ	EBI	WGS	4+8 or more
OB	EBI	Direct submissions	2+6
OC	EBI	Direct submissions	2+6
OD	EBI	Direct submissions	2+6
OE	EBI	Direct submissions	2+6
OF	DDBJ	Patent	2+6
OG	DDBJ	Patent	2+6
OH	DDBJ	EST	2+6
OI	DDBJ	Patent	2+6
OJ	DDBJ	Patent	2+6
OK	NCBI	Direct submissions	2+6
OL	NCBI	Direct submissions	2+6
OM	NCBI	Direct submissions	2+6
ON	NCBI	Direct submissions	2+6
OO	NCBI	Patent	2+6
OP	NCBI	Direct submissions	2+6
OQ	NCBI	Direct submissions	2+6
OR	NCBI	Direct submissions	2+6
OS	NCBI	Patent	2+6
OT	NCBI	Patent	2+6
OU	EBI	Direct submissions	2+6
OV	EBI	Direct submissions	2+6
OW	EBI	Direct submissions	2+6
OX	EBI	Direct submissions	2+6
OY	EBI	Direct submissions	2+6
OZ	EBI	Direct submissions	2+6
PA	DDBJ	Patent	2+6
PAA-PZZ	NCBI	WGS protein	3+5
PAAA-PZZZ	NCBI	WGS	4+8 or more
PB	DDBJ	Patent	2+6
PC	DDBJ	Patent	2+6
PD	DDBJ	Patent	2+6
PE	DDBJ	Patent	2+6
PP	NCBI	Direct submissions	2+6
PR	NCBI	Patent	2+6
PRJDA	DDBJ via NCBI	BioProject	5+5
PRJDB	DDBJ	BioProject	5+6 or more
PRJEA	EBI via NCBI	BioProject	5+5
PRJEB	EBI	BioProject	5+6 or more
PRJNA	NCBI	BioProject	5+6 or more
PS	NCBI	scaffold/CON	2+6
PT	NCBI	Patent	2+6
QAA-QZZ	NCBI	protein	3+5
QAAA-QZZZ	NCBI	WGS	4+8 or more
R	NCBI	EST	1+5
RAA-RZZ	NCBI	WGS protein	3+5
RAAA-RZZZ	NCBI	WGS	4+8 or more
S	NCBI	Journal Scanning	1+5
SAA-SZZ	EBI	protein	3+5
SAAA-SZZZ	NCBI	WGS	4+8 or more
SAMD	DDBJ	BioSample	4-5+6 or more
SAME	EBI	BioSample	4-5+6 or more
SAMN	NCBI	BioSample	4-5+6 or more
SRA	NCBI	SRA submissions	3+6 or more
SRP	NCBI	SRA sample	3+6 or more
SRR	NCBI	SRA runs	3+6 or more
SRX	NCBI	SRA experiment	3+6 or more
SRZ	NCBI	SRA analysis object	3+6 or more
T	NCBI	EST	1+5
TAA-TZZ	NCBI	WGS protein	3+5
TAAA-TZZZ	DDBJ	TLS	4+8 or more
U	NCBI	Direct submissions	1+5
UAA-UZZ	NCBI	protein	3+5
UAAA-UZZZ	EBI	WGS	4+8 or more
V	EBI	Direct submissions	1+5
VAA-VZZ	EBI	protein	3+5
VAAA-VZZZ	NCBI	WGS	4+8 or more
W	NCBI	EST (previously EBI)	1+5
WAA-WZZ	NCBI	protein	3+5
WAAA-WZZZ	NCBI	WGS	4+8 or more
X	EBI	Direct submissions	1+5
XAA-XZZ	NCBI	protein	3+5
XAAA-XZZZ	NCBI	WGS	4+8 or more
Y	EBI	Direct submissions	1+5
YAAA-YZZZ	DDBJ	TSA TPA	4+8 or more
Z	EBI	Direct submissions	1+5
ZAAA-ZZZZ	DDBJ	TLS TPA	4+8 or more

RefSeq Accession Format

The RefSeq projects are NCBI sequence annotation projects and are not part of INSDC. RefSeq accession numbers can be distinguished from INSDC accessions by their distinct format of including an underscore in the third position.

GenBank

Public nucleic acid sequence repository

Accession Number prefixes: Where did the data originate?

INSDC Accession Prefix Format

RefSeq Accession Format