Provisional sum v's PC Sum
Firstly we will go into the difference between Provisional Sums and PC Sums, the difference just isn't the terminology they both have different legal implications.
Provisional Sum
Definition:
A Provisional Sum is an estimate for both supply and labour for a part of the work that cannot be clearly defined at the time of contract.
Used for work where scope is uncertain (e.g., siteworks, landscaping, drainage).
Once the work is better defined, the actual cost replaces the provisional sum.
Legal Implication:
The contractor must prove actual cost of the work (labour + materials) to claim payment.
If the final cost is higher or lower than the provisional sum, the contract price is adjusted accordingly.
The contractor often takes on less risk for this portion of work, since it’s treated as an estimate.
PC Sum
Definition:
A PC Sum is an allowance in the contract for the supply (only) of specific items that are not yet selected at the time of contract signing. These are typically fixtures and fittings (like taps, tiles, appliances).
The cost includes supply only, not installation.
Contractor is to provide for installation cost separately.
The client will choose the actual item later, and if it costs more or less than the PC sum, the contract price is adjusted.
Legal Implication:
It's a fixed allowance for materials to be selected by the owner.
The builder has no legal obligation to install more than what the PC sum covers unless a variation is agreed upon.
Adjustments are made based on actual supplier invoice, not estimates.
How do we account for these in Rave?
Select your Project and click on the Progress Payments tab
Option #1 -
Track Provisional or PC Sum over and unders through "Variations" .
Once actuals are known:
For a PC Sum, raise a variation if the client selects a higher or lower cost item.
For a Provisional Sum, raise a variation when the final job cost is confirmed.
Attach supporting invoices or timesheets if needed for transparency.
Best practice would be to do this as a 'Detailed Invoiceable' so you can show your clients the credit back of the PC or Provisional Sum with the next line item showing the actual cost. (screenshot below)
Being able to attach documents to your variation is also an important step not to be missed. This will provide your clients all the information they require. Adding a client note is also another good way for your client to see attachments and detailed information around the variation.
Adding an Attachment to the Variation
Adding a Client Comment & Attachment
Note: When raising a Variation you will need to "Mark as Approved" manually via the 3dot drop down - this is not something you want your client to have the power to accept or decline.
Option #2
Track Provisional or PC Sum over and unders through "Others".
Once actuals are known:
For a PC Sum, raise a variation if the client selects a higher or lower cost item.
For a Provisional Sum, raise a variation when the final job cost is confirmed.
Attach supporting invoices or timesheets if needed for transparency.
Best practice would be to do this as a 'Detailed Invoiceable' so you can show your clients the credit back of the PC or Provisional Sum with the next line item showing the actual cost. (screenshot below)
Being able to attach documents to your variation is also an important step not to be missed. This will provide your clients all the information they require. Adding a client note is also another good way for your client to see attachments and detailed information around the variation.
Once saved you will see the credit ready to be invoiced through to your client - you will notice when converting to an invoice Rave will recognise that it is a credit not a debit to your client and react accordingly by creating a Credit Note. By ticking all the boxes when creating your invoice or credit note will ensure the itemised line items will show on your invoice/credit note for your client to see and of course so will the attachments.
It is Important to Note:
If your signed contract total includes Provisional Sums or Prime Cost (PC) Sums , and you choose to enter those items into the “Other” section in Rave Build (rather than within the progress payment schedule), then:
You must reduce your progress payments by the same amount —
to ensure the Total Contract Price in Rave matches your signed contract.
Why is this necessary?
In Rave, your Total Contract Price is automatically calculated as:
Deposit + Other + Progress Payments = contract value
Non Contract and Variations sit outside of the contract value but form part of the project total itself.
So if you’ve already included PC/Provisional Sums in your contract and progress payments — and then add them again in the “Other” section — they’ll be double-counted, making your contract value appear too high in Rave.
Option 1: Include PC and Provisional Sums within your progress payment schedule, and do not list them again in the “Other” section but track them through detailed invoices in your Variations Section.
Option 2: If you want to list them separately in the “Other” section for tracking, make sure to reduce the total of your progress payments by the same amount, so your figures still reconcile with your signed contract and track them through detailed invoices.