Parents of pre-admission pupils are not able to see the Lunch Money tab in School Gateway, therefore they are unable to view the lunch balance but they are still able to make payments providing the pupil is included in the payment request.
For SIMS Dinner Money payments, the pupil's balance will update on SIMS but will only become visible to the parent once the pupil is on roll.
For pre-admission payments on a Catering request (for schools using a Cashless Retailer) from a Schoolcomms perspective as the payments are made on a Catering request against a SIMS member they will be available for the retailer to pick up. As to whether the payments would be downloaded by the Cashless Retailer and the funds be available for the pupil to use in the canteen, you would need to query this with your Cashless Retailer provider.
The balances will become visible to parents in School Gateway once the pupils are on roll.