Santander's fee-free Zero card for overseas spending is now only available online if you have a current account or mortgage with the bank.

Anyone else must either apply at a branch or by phone, and is likely to get the hard-sell to take out another Santander product (see the Cheap Travel Money guide).

Anyone with a current account or mortgage with Santander-owned Alliance & Leicester can apply online for the Zero card.

The Zero credit card is our top-pick for overseas spending as there is no commission on purchases or cash withdrawals.

Most credit cards levy up to a 3% charge on overseas transactions which adds up to £3 to every £100 of spending.

However, avoid taking out cash on any credit card as interest charges are high and there is rarely an interest-free period. Santander charges a whopping 27.9% interest on cash.

Restrictions

This is the latest move by Santander to limit the availability of its best products to certain customers.

Last month, it closed its 3.2% top-paying Flexible cash Isa to online applications. Then, at the start of May, it went on sale exclusively to anyone with a Santander or Alliance & Leicester current account in branches only, or to anyone applying for one (see the Cash Isas guide).

Santander and Alliance & Leicester have good current account options, including a £100 bonus on opening (see the Best Bank Accounts guide).

Numerous other banks and building societies have also restricted their top products to customers whose primary current account is with that institution.

For example, from last summer, Nationwide's FlexAccount, the top current account for overseas spending, was made exclusively available to new customers who make it their primary current account. This means they must switch direct debits or standing orders.

Further reading/Key links

Cut costs: Cheap Travel Money
Top accounts guide: Best Bank Accounts, Cash Isas