The minimum frequency is dictated by your reporting obligations, so if you are VAT registered then the minimum is quarterly. If not, you have the option of only doing your bookkeeping annually.
The maximum frequency is dictated by how much value you get from handling bookkeeping beyond the minimum requirement. Completing your bookkeeping enables you to obtain management reporting, such as P&L reporting and Balance Sheet, which you can access easily within your Xero account (we will show you how if you would like this). In practice, this means that most small and mid-sized businesses opt for quarterly bookkeeping, with larger businesses that rely more on management reporting for strategic decisions opt for monthly.
We currently discount the fee vs the price for monthly bookkeeping by 25% for quarterly and by 43% for annual bookkeeping.