Right now the PAYG withholding scale (Scale 1 through Scale 7) is one setting in Global Controls, and it applies to every client's quotes at once. There's no way to give one client a different scale from everyone else.
A client needs all their employees quoted using the "no tax-free threshold" scale, because none of their staff claim the threshold. Because the setting is global, we can't do this without changing quotes for every other client too.
Objective
A client can be set up so their quotes use a specific PAYG scale, different from the system default, without affecting any other client. If nothing is set for a client, quoting behaves exactly as it does today.
In scope / Out of scope
In scope: a client-level setting for PAYG scale, and quote generation checking that setting before falling back to the global default.
Out of scope: changing how the global default itself works, building an interface for bulk-editing scales across many clients at once, and anything to do with payroll or repayment calculations that happen after a quote is accepted. That last one is a genuine unknown, not a decision, and it's called out below.
Functional requirements
Where the setting lives. Add a PAYG scale field at the client level, sitting alongside the client's other configuration. It should be optional. A blank value means "use the system default," which is the current behaviour for every existing client, so nobody needs to be migrated or touched.
What quoting does with it. When a quote is generated, the quoting logic checks the client's own PAYG scale setting first. If one is set, use it. If not, fall back to the global Scale setting, same as today. This needs to sit in the one place quotes actually read the scale from, not be duplicated logic bolted on beside it, or the two will drift out of sync over time.
The assumption worth naming. The request assumes the PAYG scale only matters for quote generation. We don't actually know that yet. If the same Global Controls value is also read anywhere downstream, such as actual payroll deductions, repayment schedules, or anything exported to an employer's payroll system, then this isn't a contained quoting change any more, it's a change to numbers that affect real pay. That needs to be confirmed with engineering before this is scoped as "quote-only," and if it turns out the scale is used more widely, this brief and its cost estimate need to be revisited, not quietly extended to cover it.
Who decides the client should be on Scale 1. Whether a given client's workforce genuinely doesn't claim the tax-free threshold, and therefore should be on Scale 1, is a call for the client and their accountant or payroll adviser, not something Catch-e is signing off on. The system should let the value be set and should not try to validate or second-guess which scale is "correct" for a client.
Validation and audit
Changing a client's PAYG scale should require the same permission level as other client-level configuration changes, not be editable by anyone who can view the client record.
The change should be logged: who changed it, when, and what it changed from and to. If a client is quoting under the wrong scale for months because someone fat-fingered a setting with no record of it, that's a real problem for both the client and for us.
Worth a confirmation prompt on save, along the lines of "this will change the PAYG scale used for all future quotes for this client," so it's clear this isn't a one-off, quote-specific change.
Existing quotes already generated under the old (default) scale should not be retroactively recalculated. The new setting only applies going forward.
Acceptance criteria
A client with no PAYG scale override set produces quotes identical to current behaviour. This must not change for any existing client.
Setting a PAYG scale on one client changes quotes for that client only. Quotes for every other client are unaffected.
Clearing an override on a client returns that client to the global default on the next quote generated.
Changing the override is restricted to users with the appropriate permission, and the change is recorded in an audit log with who, when, and old/new value.
Before this is built, engineering has confirmed whether the PAYG scale setting is read anywhere outside quote generation. If it is, this brief gets revisited before work starts.