For each transaction, you can attach up to 5 receipts or reference materials per transaction (maximum 2MB per transaction). File formats are supported for common images, documents, some videos and zip files. If you enter through automatic recurring transactions, only the first transaction entered will be attached to the file.
All uploaded files are changed in size and quality appropriately for convenience and storage efficiency. It may also be automatically compressed further on the server after some time passes after uploading. The storage function is not an essential part of whooing, so it prioritizes whooing's management cost savings over the original one. Therefore, it is recommended not to use it for storing the original.