Retainer Replenishment Trigger

Excel Formulas › Legal & Billing

All versionsIF

An evergreen retainer must be topped up when the balance falls below a floor. The trigger is simple — if the remaining retainer drops under the threshold, request a refill back to the original amount.


Quick formula: replenishment needed to restore the retainer:
=IF(balance < floor, target - balance, 0)
If the balance is below the floor, the top-up is whatever restores it to the target; otherwise zero.

Functions used (tap for the full reference guide):

The example

$1,200 left, $2,500 floor, $10k target.

AB
1ItemValue
2Below floor?Yes
3Top-up→ $8,800

The formula

The formula:

=IF(balance < floor, target - balance, 0) // refill to target when below the floor

How it works

How it works:

  1. Compute the current balance = retainer deposited − fees applied.
  2. IF the balance is below the floor, the top-up restores it to the target.
  3. If the balance is at or above the floor, the top-up is zero — no request.
  4. Wrap in MAX(…, 0) so a negative never appears if the balance overshoots.

Floor and target are two different numbers. The floor is when you ask (e.g. below $2,500); the target is how much you ask for (back to $10,000). Setting the floor above zero gives you runway to collect the top-up before the trust actually empties — so work never stops for lack of funds. Automate the flag and the replenishment amount falls out of one IF.

Try it: interactive demo

Live demo

Balance, floor, target.

Top-up:

Variations

Current balance

Deposited − applied:

=deposited - fees_applied

Guard against negative

Never below zero:

=MAX(target - balance, 0)

Months of runway

At average burn:

=balance / avg_monthly_fees

Pitfalls & errors

Floor ≠ target. The floor triggers the ask; the target is the refill amount.

Floor above zero. Leave runway to collect before the trust empties.

Trust rules apply. Unearned retainers sit in trust — this is illustrative, not advice.

Practice workbook

📊
Download the free Retainer Replenishment Trigger practice workbook
A retainer sheet with the balance, guard, and runway variants, plus 4 challenges with answers. No sign-up required.

Frequently asked questions

How do I trigger a retainer replenishment in Excel?
Use IF on the balance vs a floor: =IF(balance < floor, target - balance, 0) returns the top-up needed to restore the target.
Why set the floor above zero?
It gives runway to collect the top-up before the retainer empties, so work doesn't stop for lack of funds.
How do I avoid a negative top-up?
Wrap in MAX: =MAX(target - balance, 0) so an overshoot never produces a negative request.

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Function references: IFMAX