TLDR:
Issued shares are the total number of shares that a company has actually issued to shareholders from its pool of authorized shares, including both outstanding shares and treasury shares held by the company.
Managing Issued Shares Over Time
As a startup grows through multiple funding rounds, the number of issued shares increases with each new equity issuance — new investor rounds, option exercises, and warrant conversions all add to the issued share count. Managing the issued share count relative to the authorized share count is an ongoing governance responsibility: when issued shares approach the authorized ceiling, the company must approve an increase in authorized shares (typically requiring shareholder approval). Well-run startups maintain a ‘reserve’ of authorized but unissued shares to accommodate future equity needs without emergency governance actions.
Issued vs. Authorized vs. Outstanding
Three related but distinct concepts: authorized shares are the maximum number permitted by the articles of incorporation; issued shares are those that have been distributed to shareholders; outstanding shares are issued shares that have not been repurchased by the company (treasury shares). The distinctions matter for ownership calculations, voting rights, and authorized-share availability for new issuances. Boards must monitor authorized headroom and propose increases via stockholder vote when running close to the cap.
Issuance Mechanics
Each share issuance requires board approval and proper documentation: stock certificates or book-entry registrations, updates to the stock ledger and cap table, securities-law compliance (federal exemption analysis and state filings), and tax reporting where applicable. Modern cap-table platforms (Carta, Pulley, AngelList Stack) automate most of this work, but the legal validity of issuances depends on proper board consents and required stockholder approvals.