Up to three years if the affiliate has been doing business for more than a year; one year if it is a new office. Extensions come in two-year increments up to a seven-year total, and the assignment plan should reflect which case applies.
Match the assignment to the approval period
An L-1A petition for an established U.S. office can be approved for up to three years, which would cover the planned assignment in a single approval. If the affiliate began doing business less than a year before filing, the petition is a new-office case with an initial approval of one year and additional evidence about premises and the plan to support a managerial role, and the extension at the end of that year must show the office is operating.
Determine which applies from the affiliate's first invoices and payroll, not its incorporation date. After the initial period, extensions are granted in two-year increments to a maximum of seven years in L-1A status, counting any prior L time. Build in the petition preparation time, the adjudication period with or without premium processing, and her admission at the port of entry with the approval notice.
Do not let the affiliate announce her start date until the qualifying year abroad is complete and the evidence of delegation is in hand.