I'm doing some benchmarking on internal movement / cross boarding guidelines or policy in the high-tech industry. I'm looking to understand best practices for sharing internal openings, any parameters about time in role, ability to apply for higher level and if promotion given at time of successful application, etc? How do you manage budget for promotions if given at time of successful application, etc.?

We have some parameters in policy to manage internal applicants. Generally speaking, time-in-role requirements are 12 months for office assignments, 18 months for domestic field assignments and 24 months for international assignments. These differences are for a few reasons… we’re a project-based company and relocation costs (as well as expat costs for international assignments) are typically factored in and these time periods are assumed to level the investment before an employee changes assignments. Plus, field and international assignments are assumed to be more of a stretch or development assignment, hence the desire to stay in the role a little longer. These time-in-role requirements can be waived with proper approval, based upon business needs.
Our general practice is to give the employee the promotion upon he/she assuming the new role. Budget is always a factor but typically our teams are large enough and fluid enough (several transfers in/out and associated time with empty roles) that the budget is offset but this is something we have to monitor and consider.

A promotion policy is a set of guidelines that outline how and when employees can be promoted. A good promotion policy can help build trust between employees and management and ensure that promotions are fair and based on merit.
Eligibility criteria: Clearly define who can be promoted and what qualifications are required. This can include factors like performance and other relevant qualifications.
Promotion process: Explain what employees can expect when applying for a promotion, including how to submit applications, the evaluation process, and timelines. These currently occur throughout the year at many companies rather than on a cycle (e.g., annual, twice a year or quarterly)
Decision authorities: Identify who will make promotion decisions, such as HR managers, leadership, or direct supervisors.
Internal job postings: Encourage hiring managers to post job openings internally. I suggest an internal mobility AI application (Workday Talent Marketplace) is something to consider. Many organizations have a policy of 6-12 months before someone can move to a lateral job. Promotions maybe an exception.
Communication: A clear promotion policy can help employees understand what is expected of them and how they can progress in their careers.
Budget: Organizations typically budget between .5% or 1% of payroll for promotions* Currently this is considered an issue because many organizations don't have a separate budget for promotions.
Promotional Increase Amount: Promotional increases typically range from 8 to 15%. The median promotional increase is 9.5% from WorldatWork.