The minimum contribution you can make to any CIRCA5000 account is £5. This applies to one-off contributions, monthly contributions and round-ups.

If your round-ups in any given week is less than £5, then the balance will continue to carry over to the following week until the minimum amount is at least £5 and can be collected.

There is no maximum amount you can add to a CIRCA5000 GIA.

Some banks might have their own card payment limit; so if you're trying to add more than your bank will allow in a single contribution, then you may need to make several smaller contributions.

ISA rules mean you can only add up to the ISA allowance per tax year across all of your ISAs.

The ISA allowance for the 2023-24 tax year is £20,000; so you cannot add more than this amount to your CIRCA5000 ISA for this tax year.

Please be aware some banks may have their own card payment limit; so if you're trying to add more than your bank will allow in a single contribution, then you might need to make several smaller contributions.

You can read more about ISAs here: https://www.gov.uk/individual-savings-accounts.

JISA rules mean you can only add up to the JISA allowance per tax year across your child's JISAs.

The JISA allowance for 2023-24 is £9,000, so you cannot add more than this amount to your child's CIRCA5000 JISA for this tax year.

Please be aware some banks may have their own card payment limit; so if you're trying to add more than your bank will allow in a single contribution, then you might need to make several smaller contributions.

You can read more about JISAs here: https://www.gov.uk/junior-individual-savings-accounts.