D.C. Mun. Regs. tit. 3 § 602
In the case of a primary election, a write-in nominee who wishes to perfect their candidacy shall file with the Board an Affirmation of Write-in Candidacy on a form provided by the Board not later than 5:00 p.m. on the third (3rd) day immediately following the election.
In the case of a general or special election, a write-in nominee who wishes to perfect their candidacy shall file with the Board an Affirmation of Write-in Candidacy on a form provided by the Board not later than 5:00 p.m. on the seventh (7th) day immediately following the election.
Nothing in this section shall prohibit an individual seeking to declare write-in candidacy from filing an Affirmation of Write-in Candidacy prior to write-in nomination, provided that the determination of the write-in candidate's eligibility shall proceed in accordance with this chapter. Write-in nominees who fail to submit the documents required by this section within the prescribed times shall be deemed to be ineligible candidates.
The Affirmation of Write-in Candidacy form shall contain the same information required for the Declaration of Candidacy described in this chapter.
Each write-in candidate shall swear under oath or affirm before a District of Columbia notary or Board official that the information provided in the Affirmation of Write-in Candidacy is true to the best of his or her knowledge and belief.
If a write-in nominee is an apparent winner of an election contest, the Executive Director or his or her designee shall issue a preliminary determination as to the eligibility of the write-in nominee if such nominee has perfected his or her candidacy on or before the prescribed deadline. No eligibility determination shall be made for affirmants who are not apparent winners.
Notice of any adverse determination shall be served immediately by mail and/or email to the email address for the person identified on the Affirmation of Write-in Candidacy form.
The determination of eligibility shall be based solely upon information contained in the Affirmation of Write-In Candidacy and upon information contained in other public records and documents as may be maintained by the Board. The criteria used for determining eligibility to be a candidate shall be limited to the appropriate statutory qualifications for the particular office sought.
The determination shall in no way be deemed to preclude further inquiry into or challenge to such individual's eligibility for candidacy or office made prior to the certification of election results by the Board and based upon information which is not known to the Board at the time of the preliminary determination, or upon evidence of changed circumstances.
If a write-in winner is declared ineligible after the election, no winner shall be declared.
Notice of the successful bid of a write-in candidate shall be provided through the posting of election results on the Board's website. No other notice is required.
D.C. Mun. Regs. Tit. 3, § 602