As long as you do not need to issue a receipt for the pledge, just receive payments, QB does not care who paid it

If you do need to issue a receipt, the original pledge is void, and you create a new one, and receive payments, or just use a sales […]

Resolution for 'another persons pledge issue: 'How can I record a donation from someone to another persons pledge?' available: Yes.

The another persons pledge issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the another persons pledge issue yourself by looking for a resolution described in the article. If it is a complex another persons pledge issue or you are unable to solve the issue, you may contact us by clicking here or by using other another persons pledge support options.

For more information about resolving issues related to another persons pledge in Quickbooks/QBO or to get support for the issue 'How can I record a donation from someone to another persons pledge?', click the link below: