How a promotional code works
A promotional code is a voucher that puts credit on an ads account. It is entered in the account’s own billing section, not at signup, and it comes with conditions attached rather than being applied on sight. Typically the account must be new, the code must be entered within a window after the account was created, and the advertiser must spend a qualifying amount from their own payment method inside a set period before the credit is released.
Two details catch people out. The credit applies to future spend only — it never refunds what you have already paid — and codes are issued for a particular country and currency, so one intended for another market will not apply to your account. Unused credit also expires. Once it is on the account it behaves like a balance, drawn down as costs accrue, and it does nothing to how the auction treats you.
Why promotional codes matter
Mostly as a small subsidy on the learning period. Every new account starts without conversion history, so early spend buys data as much as it buys enquiries, and a credit softens that first stretch. For a small business testing whether paid search works at all, that is a reasonable use.
What a code does not do is more important. It does not improve your position, lower your cost per click, or make a badly targeted campaign work. Credit spent on the wrong keywords disappears exactly as fast as money would, and it teaches you nothing except that the account can spend.
Where promotional codes go wrong
The most frequent problem is timing. The code was received when the account was created, the campaign was not ready for another month, and by the time anyone entered it the window had closed. The second is the qualifying spend: advertisers assume the credit arrives immediately, run a small test, and never reach the threshold that releases it.
Then there are codes from third parties. A code passed around online, resold, or bundled with a hosting package is often already redeemed, tied to a different currency, or restricted to accounts created through a particular route. If a code will not apply, the cause is almost always one of those conditions rather than a fault in the account.
The worst outcome is a budget planned around the credit. Spending in the qualifying period is real money leaving the business, and the campaign has to be worth running without the voucher.
What to do about it
Read the conditions on the code before you plan anything, and note the deadline for entering it and the spending requirement that releases it. Enter it once the campaigns are genuinely ready, not on the day the account is opened, so the qualifying spend goes on work you would have done anyway.
Set the budget from what the enquiries are worth to you rather than from the credit; a Google Ads budget calculator is a more honest starting point than a voucher. Then watch the balance and the charges together, because credit and card spend appear in the same place and the billing threshold resumes as soon as the credit runs out.