What about a pre-approval process?
ExpensePlus doesn't offer a pre-approval process for expenses.
Typically having a pre-approval process is not recommended, since it is inefficient.
Most churches and charities instead have a simple one-page purchasing policy that states that for purchases under £20, for example, no pre-approval is needed.
Verbal approval is needed from the budget holder if the purchase is over £20 (but under say £500), and written approval (via email) is needed if the purchase is over £500.
Some organisations find it helpful to get all staff and volunteers to read and sign the purchasing policy before giving them access to submit purchases in ExpensePlus.
Whether you have a pre-approval process or not, you can't actually stop someone from buying something for your organisation using their own money (so a pre-authorization doesn't really stop anything). But, having a purchasing policy lays out a clear expectation at which verbal/written approval is required and if this isn't followed, you can be clear that you won't reimburse the purchase.
Approvals in ExpensePlus
If someone makes a purchase and doesn't follow the purchasing policy, then when the budget holder comes to approve the expense, they can then decide to not approve it and the expense claim won't get paid.
In reality, you would have a conversation with that person along the lines of, "Please don't do this again, because we will only pay expenses if you follow our purchasing policy".
Business Card Purchases
If staff members have a church or charity debit/credit card, then typically you'd have a separate cardholder policy.
Cardholders would be asked to sign. As part of that, it would include something saying "The purchasing policy must be followed, and if it isn't you will forfeit your access to having a church/charity debit/credit card".
This would mean that the person would have to go back to claiming purchases on expenses and giving you the option to choose to not reimburse them if they don't follow the purchasing policy with regards to pre-authorization approval.
Limits for pre-authorisation
In terms of what limits you set for pre-authorization, typically these want to be high enough so that most regular purchases don't require pre-authorization.
As well as stating pre-authorization thresholds, most purchasing policies also state other criteria for making purchases, such as the purchase being 'needed', 'value for money', 'within budget', etc.
To find templates for a purchasing policy and card holder policy, view this blog post on purchasing policies for churches.
To help you better understand the Approvals module as a whole, please visit the module overview page here.