Amendments change the future, not the past.
Nothing, by default: an amendment works forward from its effective date. Anything earlier changes only if you change it on purpose, in an open period.
Background
Many federal awards allow a one-time extension of up to 12 months without new money, if you tell the agency at least 10 days before the end date.
You cannot extend just to spend down leftover money, and most other changes need written approval first.
Three cases
01A no-cost extension
What is already billed does not change. Costs dated after the old end date have probably been sitting on hold.
After the dates move, check that those held costs reach ready to bill. Depending on your setup, you may have to release or reprocess them yourself.
Move any closing flags or closeout tasks set for the old end date.
02More funding
The new authorized amount applies from the effective date. If billing was capped, the rest can go out on the next invoice. Invoices already sent stay as they are.
03An overhead rate change
Going forward, new costs get the new rate and old costs keep the old one. If the sponsor makes it retroactive, recalculate on purpose, in an open period, and bill the difference.
On $200,000 of costs, going from 50% to 52% is $4,000 more.
Two ways to take this further
The free health check runs sixteen checks on your grants area, and the free Effort Certification Review tests your own export in your browser.
The Sponsored Award Review is the scored version, $1,950 for your whole institution.
More guides like this: Workday Grants guides from an independent consultant.