NCBI staff assign GenBank accession numbers at the end of the sequence submission process. During the submission process, numerous temporary identifiers will accompany the data. In addition to the temporary IDs that submitters assign to their individual sequences, submitters also receive various submission identifiers (assigned automatically by the NCBI submission software). Some examples of submission identifiers are BankIt numbers assigned to submissions prepared through the BankIt submission tool and various “SUB” numbers assigned to submissions prepared through the NCBI Submission Portal. The submission identifiers should not be confused with GenBank accession numbers, and they are not suitable for listing in publications.

Once a submission is received, GenBank staff will review the sequence data and their annotation.  If there are no problems* with the submission, they will assign (usually within a couple of working days) an accession number to each individual sequence record. Sequences in the same submission set or batch will receive successive accession numbers. The accession numbers will be provided with prefixes that are in use at the time of the submission.

If you are submitting to GenBank, note that your temporary IDs will be replaced with the accession numbers. Any information that you embed in your IDs will subsequently be lost. Therefore, you should provide your sequence source information as separate source modifiers.

*GenBank staff will contact the submitters and ask them to address any problems and/or provide any lacking information before they can assign the accession numbers.