Is a letter of recommendation accepted as a reference?

I’m applying for a live in housekeeping job. I have a letter of recommendation from my previous housekeeping job which includes the address, name and email. Is this enough to produce as a reference, or would a new employer also require a phone number?
Answers

Success

Yes, indeed it is.

Maxi

Some would some wouldn't...... any reference given is likely to be checked anyway

Katie

Yes, ONLY if you have NOT seen or handled it - unless the new employer has got it directly from the employer who wrote it it will be classed as a forgery.

Anonymous

Yes. You should include a phone number.