The petition filing charge and optional premium processing, published in the USCIS fee schedule, plus the professional work of assembling group and employment evidence.
Historic record retrieval is the cost companies underestimate
The published charges are straightforward and the employer bears them, since L-1 is an employer-filed petition. The unpredictable expense is evidence assembly, and a case relying on service with an overseas affiliate is heavier than a simple one. Someone must obtain certified corporate records from another jurisdiction, retrieve payroll from a former group company, reconcile employment dates across systems, and write a support letter that describes managerial authority accurately.
Where records are held by a business that has since been sold or restructured, retrieval can be slow and occasionally impossible, which is itself a reason to start early. Budget for a possible request for further evidence, since a qualifying year assembled across two countries invites scrutiny. Premium processing shortens adjudication but does nothing for retrieval, and paying for it before the file is complete is the wrong sequence.