Commitment versus contribution
In a commitment-based vehicle you agree a total amount but fund it in stages. Your commitment is the promise; your contribution is what you have actually paid. The difference is unfunded commitment, and it remains an obligation.
How a call is computed
A call states a total amount the vehicle needs and a due date. Each investor's share is usually pro-rata to unfunded commitment, though governing documents can specify otherwise for particular classes or for equalisation at an interim closing.
Missed calls
Governing documents set out remedies for a defaulted call — commonly interest charges, dilution of interest, forced transfer, or forfeiture. These provisions are consequential and should be read before signing, not after a call arrives.