What is a subscription line?
A subscription line is a revolving credit facility extended to a fund by a bank, secured not by the fund's assets but by the uncalled capital commitments of its limited partners. The lender's collateral is, in effect, the GP's right to call capital from creditworthy investors.
The GP draws on the line to pay for investments and expenses upfront, then repays the bank by calling capital from LPs later — often in larger, batched calls rather than a steady stream of small ones. The facility bridges the gap between when cash is needed and when it is drawn from investors.
What began as an administrative convenience — smoothing capital calls and avoiding the operational friction of frequent small draws — has become a significant lever on reported fund performance, which is why it draws scrutiny.
Why subscription lines affect IRR
IRR is a time-weighted measure: it rewards getting capital back quickly relative to when it was deployed. A subscription line manipulates the deployment timing:
- The fund buys early, calls late. The line funds the investment now; the LP capital call happens months later.
- The clock starts later. Because IRR is measured from when LP capital is actually called, delaying the call shortens the period the LP money is "at work."
- IRR rises, MOIC doesn't. The same profit over a shorter measured holding period produces a higher IRR — while the multiple of money (MOIC) is essentially unchanged, less the interest cost.
The effect is real but partly cosmetic. The line does not make the underlying investments better; it shifts the timeline against which returns are measured. Heavy, sustained use can meaningfully inflate headline IRR relative to a fund that called capital conventionally.
The trade-offs and the scrutiny
Subscription lines carry genuine benefits: fewer and more predictable capital calls for LPs, the ability to move quickly on a deal, and simpler fund administration. But they also carry an interest cost borne by the fund, introduce leverage at the fund level, and — most controversially — make cross-fund IRR comparisons unreliable unless everyone discloses their facility use.
Because of this, institutional LPs and bodies such as the ILPA have pushed for clearer disclosure: reporting IRR both with and without the effect of the line, and capping how long facilities stay outstanding. The honest read of a levered IRR is to ask what the return would have been if capital had been called on day one.