There’s a combined cap of $1,000,000 across all account types and challenge types, based on starting balance only. It’s one total limit, not a separate $1,000,000 per programme.
This means scaling doesn’t count against your cap. If an account grows through a scaling plan, only the original starting balance is counted — the scaled-up portion is excluded.
For example: if you already have $200,000 allocated in Instant Funding Smart Funding and $400,000 in One Phase Funding, that’s $600,000 of your $1,000,000 cap used, leaving $400,000 of headroom for other challenge types. If that One Phase Funding account later scales from $400,000 to $500,000, your allocation used still counts as $400,000, not $500,000 — so your remaining headroom stays at $400,000 rather than shrinking.